2. Networking Flashcards

1
Q

Ports and protocols of 20/21.

A

FTP stands for File Transfer Protocol and is used to transfer files between computers on a network.

FTP uses two ports: port 21 for control information (such as login credentials and commands), and port 20 for data transfer.

FTP uses TCP as its transport protocol, which ensures reliable delivery of data.

FTP can operate in two modes: active mode and passive mode. In active mode, the client computer sends a port number to the server, which then initiates a connection to that port on the client computer. In passive mode, the client initiates the connection and the server sends a port number for the client to connect to.

FTP can be secured using SSL/TLS encryption, which adds an additional layer of security to the data transfer process.

FTP is often used by website administrators to upload files to a web server, and by users to download files from public servers.

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2
Q

Ports and protocols of 22.

A

SSH stands for Secure Shell and is used to securely connect to and manage remote computers over a network.

SSH uses port 22 by default, but this can be changed if necessary.

SSH uses TCP as its transport protocol, which ensures reliable delivery of data.

SSH provides encrypted communication between the client and server, which prevents unauthorized access and eavesdropping.

SSH uses public-key cryptography to authenticate the client and server, which adds an additional layer of security.

SSH can be used to execute commands on a remote computer, transfer files between computers, and forward ports between computers.

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3
Q

Ports and protocols of 23.

A

Telnet is a protocol used for remote access to computers over a network.

Telnet uses port 23 by default, but this can be changed if necessary.

Telnet uses TCP as its transport protocol, which ensures reliable delivery of data.

Telnet does not provide encrypted communication, which means that all data sent between the client and server is sent in clear text, making it vulnerable to interception and eavesdropping.

Telnet is typically used for accessing legacy systems and network devices, such as routers and switches.

Telnet can be secured using Secure Shell (SSH) or Virtual Private Networks (VPNs) to encrypt communication.

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4
Q

Ports and protocols of 25.

A

SMTP stands for Simple Mail Transfer Protocol and is used to transfer email messages between servers.

SMTP uses port 25 by default, but can also use ports 587 and 465 for secure email transmission.

SMTP uses TCP as its transport protocol, which ensures reliable delivery of data.

SMTP can be secured using Transport Layer Security (TLS) or Secure Sockets Layer (SSL) encryption, which encrypts the communication between the email client and server, protecting the email content and login credentials.

SMTP can also be used to receive email messages from other servers, in which case it is referred to as POP3 or IMAP.

SMTP is a widely used protocol for sending and receiving emails and is supported by most email clients and servers.

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5
Q

Ports and protocols of 53.

A

DNS stands for Domain Name System and is used to translate domain names (such as www.example.com) into IP addresses (such as 192.0.2.1) that can be understood by computers on a network.

DNS uses port 53 by default for both TCP and UDP protocols.

DNS uses TCP for zone transfers and larger queries, and UDP for regular queries and responses.

DNS is a distributed system, which means that it consists of many servers that work together to provide domain name resolution.

DNS can be configured to use forwarders and root hints to resolve queries when it does not have the answer in its cache.

DNS can be secured using Domain Name System Security Extensions (DNSSEC), which provides authentication and integrity of DNS data.

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6
Q

Ports and protocols of 67/68.

A

DHCP stands for Dynamic Host Configuration Protocol and is used to automatically assign IP addresses and other network configuration information to devices on a network.

DHCP uses ports 67 and 68 for server-client communication, with the server using port 67 and the client using port 68.

DHCP uses UDP as its transport protocol, which allows for fast and efficient communication between the server and clients.

DHCP can provide a range of network configuration information to clients, including IP address, subnet mask, default gateway, and DNS server addresses.

DHCP can be configured to provide IP addresses dynamically or statically, with dynamic allocation being the most common method.

DHCP can be configured to provide IP addresses to different types of devices, including desktops, laptops, mobile devices, and servers.

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7
Q

Ports and protocols of 80.

A

HTTP stands for Hypertext Transfer Protocol and is used for transmitting data over the internet.

HTTP uses port 80 by default for unencrypted communication, and port 443 for encrypted communication using HTTPS.

HTTP uses TCP as its transport protocol, which ensures reliable delivery of data.

HTTP is used by web servers to transmit data to web browsers, including HTML pages, images, and other media.

HTTP requests are initiated by the client (web browser) and responses are sent by the server, with each request and response consisting of a series of headers and a message body.

HTTP can be secured using HTTPS, which encrypts the communication between the client and server, protecting sensitive data from interception and eavesdropping.

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8
Q

Ports and protocols of 110.

A

POP3 stands for Post Office Protocol version 3 and is used for retrieving email messages from a mail server.

POP3 uses port 110 by default for unencrypted communication, and port 995 for encrypted communication using POP3S.

POP3 uses TCP as its transport protocol, which ensures reliable delivery of data.

POP3 allows email clients to download and store email messages on the client’s device, removing them from the server.

POP3 can be configured to keep a copy of the email messages on the server, allowing multiple devices to access the same messages.

POP3 can be secured using Transport Layer Security (TLS) or Secure Sockets Layer (SSL) encryption, which encrypts the communication between the email client and server, protecting the email content and login credentials.

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9
Q

Ports and protocols of 137/139.

A

NetBIOS stands for Network Basic Input/Output System and is used for communication between devices on a local network.

NetBIOS uses ports 137 and 138 for UDP communication, and port 139 for TCP communication.

NetBIOS is used for naming and browsing on a local network, allowing devices to discover and communicate with each other using their NetBIOS name.

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10
Q

Ports and protocols of 143.

A

IMAP stands for Internet Message Access Protocol and is used for retrieving email messages from a mail server.

IMAP uses port 143 by default for unencrypted communication, and port 993 for encrypted communication using IMAPS.

IMAP uses TCP as its transport protocol, which ensures reliable delivery of data.

IMAP allows email clients to access and manipulate email messages stored on the mail server, without removing them from the server.

IMAP can be configured to keep a copy of the email messages on the server, allowing multiple devices to access the same messages.

IMAP can be secured using Transport Layer Security (TLS) or Secure Sockets Layer (SSL) encryption, which encrypts the communication between the email client and server, protecting the email content and login credentials.

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11
Q

Ports and protocols of 161/162.

A

SNMP stands for Simple Network Management Protocol and is used for managing and monitoring network devices.

SNMP uses port 161 for sending requests and receiving responses, and port 162 for receiving SNMP trap messages.

SNMP uses UDP as its transport protocol, which is connectionless and does not guarantee reliable delivery of data.

SNMP consists of a manager and agents, where the manager sends requests to the agents to retrieve information about network devices, and the agents respond with the requested information.

SNMP allows the monitoring of various network parameters, such as bandwidth utilization, CPU and memory usage, and network errors.

SNMP can also be used for configuring network devices, such as changing the settings of routers and switches.

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12
Q

Ports and protocols of 389.

A

LDAP stands for Lightweight Directory Access Protocol and is used for accessing and managing directory information services.

LDAP uses port 389 for unencrypted communication, and port 636 for encrypted communication using LDAPS.

LDAP uses TCP as its transport protocol, which ensures reliable delivery of data.

LDAP allows clients to access and modify directory information stored on a server, such as user accounts and group memberships.

LDAP is used in many authentication and authorization scenarios, such as managing user accounts in an organization or granting access to resources based on group memberships.

LDAP can be secured using Transport Layer Security (TLS) or Secure Sockets Layer (SSL) encryption, which encrypts the communication between the client and server, protecting the directory information and login credentials.

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13
Q

Ports and protocols of 443.

A

HTTPS stands for Hypertext Transfer Protocol Secure and is used for secure communication over the internet.

HTTPS uses port 443 by default for encrypted communication.

HTTPS uses TCP as its transport protocol, which ensures reliable delivery of data.

HTTPS is used to encrypt and secure communication between a web browser and a web server, protecting sensitive information such as login credentials and credit card numbers.

HTTPS uses SSL/TLS encryption to encrypt the communication, which prevents eavesdropping and tampering of data in transit.

HTTPS is indicated by a lock icon in the web browser’s address bar, and the URL starts with “https://” instead of “http://”.

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14
Q

Ports and protocols of 445.

A

SMB stands for Server Message Block, and CIFS stands for Common Internet File System. They are used for sharing files, printers, and other resources between computers on a network.

SMB/CIFS uses port 445 for communication.

SMB/CIFS uses TCP as its transport protocol, which ensures reliable delivery of data.

SMB/CIFS allows users to access files and printers on remote computers as if they were local resources.

SMB/CIFS supports various authentication and authorization mechanisms, such as username and password, or Active Directory domain authentication.

SMB/CIFS can be secured using various methods, such as encryption, signing, and access control.

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15
Q

Ports and protocols of 3389.

A

RDP is a proprietary protocol developed by Microsoft and is used for remote access to Windows-based systems.

RDP uses port 3389 for communication.

RDP uses TCP as its transport protocol, which ensures reliable delivery of data.

RDP allows users to connect to a remote Windows computer and access its desktop, applications, and files as if they were sitting in front of it.

RDP supports various authentication and encryption mechanisms to secure communication between the client and server.

RDP is commonly used by IT professionals to remotely manage and troubleshoot Windows-based systems.

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16
Q

TCP vs UDP.

A

TCP vs UDP: Differences between the protocols. The main difference between TCP (transmission control protocol) and UDP (user datagram protocol) is that TCP is a connection-based protocol and UDP is connectionless. While TCP is more reliable, it transfers data more slowly. UDP is less reliable but works more quickly.

Connection-oriented vs. connectionless: TCP is connection-oriented, which means that a connection is established between the sender and receiver before any data is exchanged. UDP, on the other hand, is connectionless, which means that data can be sent without first establishing a connection.

Reliability: TCP provides reliable transmission of data by ensuring that all packets are received and in the correct order. It uses acknowledgement messages and retransmission of lost packets to achieve this. UDP, on the other hand, does not provide any guarantee of delivery or order of packets.

Error checking: TCP uses checksums to ensure that data is transmitted without errors. UDP also uses checksums, but they are optional and not always used.

Flow control: TCP uses a mechanism called flow control to prevent the sender from overwhelming the receiver with too much data. UDP does not have any flow control mechanism.

Speed: Because TCP provides reliability, it can be slower than UDP, which does not have the overhead of reliability and error checking.

Applications: TCP is commonly used for applications that require reliable data transmission, such as email, file transfer, and web browsing. UDP is commonly used for applications that require low latency and do not require reliable transmission, such as online gaming and video streaming.

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17
Q

Connectionless TCP vs UDP for DHCP.

A

Connectionless DHCP over UDP is used because it is a lightweight protocol that does not require the overhead of establishing and maintaining a connection. The DHCP server simply broadcasts DHCP packets, called DHCPDISCOVER, which are received by all devices on the network.

The devices that need an IP address to respond with a DHCPOFFER packet, and the DHCP server then selects one of the offers and sends a DHCPREQUEST packet to that device, which then responds with a DHCPACK packet. All of these DHCP packets are sent over UDP.

The use of connectionless DHCP over UDP allows for faster communication and less network overhead, as there is no need to establish a connection before transmitting data. This is important for DHCP, as the protocol is used to dynamically assign IP addresses, which can occur frequently on a network with many devices.

Overall, the use of UDP for connectionless DHCP allows for a faster and more efficient protocol than using TCP, which requires a connection to be established and maintained throughout the communication.

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18
Q

Connectionless TCP vs UDP for TFTP.

A

TFTP (Trivial File Transfer Protocol) is a simple file transfer protocol that is commonly used for transferring firmware images, configuration files, and other small files between networked devices. TFTP operates over UDP, which makes it a connectionless protocol.

Here are some key differences between TCP and UDP in the context of TFTP:

Connection-oriented vs. connectionless: TCP is connection-oriented, which means that a connection is established before any data is exchanged, while UDP is connectionless, which means that data can be sent without first establishing a connection. TFTP uses UDP, which makes it a connectionless protocol.

Reliability: TCP provides reliable transmission of data by ensuring that all packets are received and in the correct order. It uses acknowledgement messages and retransmission of lost packets to achieve this. UDP, on the other hand, does not provide any guarantee of delivery or order of packets. This means that TFTP, which uses UDP, does not guarantee the reliable delivery of data.

Error checking: TCP uses checksums to ensure that data is transmitted without errors. UDP also uses checksums, but they are optional and not always used. TFTP uses a simple checksum mechanism to verify the integrity of the data being transferred.

Flow control: TCP uses a mechanism called flow control to prevent the sender from overwhelming the receiver with too much data. UDP does not have any flow control mechanism. TFTP does not implement any flow control, which means that it is susceptible to network congestion and can result in packet loss.

Speed: Because UDP provides no guarantee of reliable data transmission, it can be faster than TCP. This means that TFTP, which uses UDP, can be faster than other file transfer protocols that use TCP.

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19
Q

Connection-oriented HTTPS and SSH.

A

Both HTTPS (Hypertext Transfer Protocol Secure) and SSH (Secure Shell) are connection-oriented protocols that use TCP as their underlying transport protocol. This means that before any data is transmitted, a connection is established between the client and the server, and this connection is maintained until the data transfer is complete.

Here are some key features of connection-oriented HTTPS and SSH:

Encryption: Both HTTPS and SSH use encryption to secure the data being transmitted over the network. HTTPS uses SSL/TLS (Secure Sockets Layer/Transport Layer Security) encryption, while SSH uses its own encryption algorithm.

Authentication: Both HTTPS and SSH use authentication mechanisms to ensure that the client is communicating with the intended server. HTTPS uses digital certificates to verify the identity of the server, while SSH uses public key authentication.

Reliable data transfer: Because both HTTPS and SSH use TCP, they provide reliable data transfer by ensuring that all packets are received and in the correct order. They use acknowledgement messages and retransmission of lost packets to achieve this.

Connection setup: Both HTTPS and SSH require a connection setup phase before any data is transmitted. During this phase, the client and server negotiate the parameters of the connection, including the encryption algorithm to be used.

Port numbers: HTTPS uses port 443 as its default port number, while SSH uses port 22 as its default port number.

In summary, HTTPS and SSH are connection-oriented protocols that use TCP as their underlying transport protocol. They both provide encryption and authentication to secure the data being transmitted over the network, and they both provide reliable data transfer by ensuring that all packets are received and in the correct order.

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20
Q

Compare and contrast common networking hardware for routers.

A

Routers: A router is a networking device that is used to connect multiple networks together. It operates at the OSI Network Layer (Layer 3) and uses logical addressing (such as IP addresses) to direct traffic between networks. Routers typically have multiple interfaces, each connected to a different network.

WAN Interface: A WAN interface on a router is used to connect the router to a Wide Area Network (WAN). This can be done using technologies such as T1/E1, T3/E3, DSL, cable, or fibre optic connections.

LAN Interfaces: LAN interfaces on a router are used to connect the router to Local Area Networks (LANs). These interfaces can be Ethernet, Wi-Fi, or other types of interfaces.

NAT: Network Address Translation (NAT) is a technology used by routers to translate between the private IP addresses used on a LAN and the public IP address used on the WAN. This allows multiple devices on a LAN to share a single public IP address.

DHCP: Dynamic Host Configuration Protocol (DHCP) is a protocol used by routers to automatically assign IP addresses to devices on a network. DHCP can also be used to assign other network configuration parameters, such as subnet masks, default gateways, and DNS server addresses.

VPN: Virtual Private Networks (VPNs) allow remote users to connect to a private network over the Internet. Routers can be configured to support VPN connections, allowing remote users to securely access the private network.

Quality of Service (QoS): QoS is a set of technologies used by routers to prioritize certain types of network traffic over others. This can help ensure that critical traffic, such as voice or video traffic, is given priority over less important traffic, such as file downloads.

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21
Q

Compare and contrast common networking hardware for managed switches.

A

Managed switches: A managed switch is a networking device that is used to connect devices within a local area network (LAN). Unlike unmanaged switches, managed switches allow for configuration and monitoring of network traffic.

VLANs: A VLAN (Virtual Local Area Network) is a logical grouping of devices within a LAN. Managed switches can be used to create VLANs, which can help with network segmentation and security.

Port Mirroring: Port mirroring is a feature of managed switches that allows network administrators to monitor network traffic by duplicating traffic from one port and forwarding it to another port. This can be useful for troubleshooting network issues or monitoring network security.

Quality of Service (QoS): QoS is a set of technologies used by managed switches to prioritize certain types of network traffic over others. This can help ensure that critical traffic, such as voice or video traffic, is given priority over less important traffic, such as file downloads.

Spanning Tree Protocol (STP): STP is a protocol used by managed switches to prevent network loops. Network loops can occur when there are multiple paths between switches in a network, which can cause network congestion or even network failures. STP helps to ensure that there is only one path between switches in the network.

Link Aggregation Control Protocol (LACP): LACP is a protocol used by managed switches to combine multiple physical links between switches into a single logical link. This can help increase bandwidth and improve network redundancy.

Port Security: Port security is a feature of managed switches that allows network administrators to limit the number of devices that can be connected to a particular switch port. This can help prevent unauthorized access to the network and reduce the risk of network attacks.

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22
Q

Compare and contrast common networking hardware for UNmanaged switches.

A

Unmanaged switches: An unmanaged switch is a basic networking device that is used to connect devices within a local area network (LAN). Unlike managed switches, unmanaged switches are plug-and-play devices that do not require any configuration or monitoring.

Port-based: Unmanaged switches operate on a port-based system, which means that all devices connected to the switch share the same bandwidth. If multiple devices are trying to communicate at the same time, network congestion and slow speeds can occur.

No VLANs: Unmanaged switches do not have the ability to create VLANs. This means that all devices connected to the switch are on the same network segment, which can make it more difficult to implement network segmentation and security measures.

No Quality of Service (QoS): Unmanaged switches do not have the ability to prioritize certain types of network traffic over others. This means that all network traffic is treated equally, which can result in slow network speeds and poor network performance.

No Spanning Tree Protocol (STP): Unmanaged switches do not have the ability to run STP. This means that network loops can occur if there are multiple paths between switches in a network, which can cause network congestion or even network failures.

No Port Security: Unmanaged switches do not have the ability to limit the number of devices that can be connected to a particular switch port. This means that any device can be connected to the network, which can increase the risk of network attacks and unauthorized access.

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23
Q

Compare and contrast common networking hardware for access points.

A

Access points: An access point (AP) is a device that allows wireless devices to connect to a wired network. Access points are commonly used to extend the range of a wireless network or to provide wireless connectivity to devices that do not have built-in Wi-Fi capabilities.

Wireless Standards: Access points support different wireless standards, such as 802.11a, 802.11b, 802.11g, 802.11n, and 802.11ac. These standards specify the maximum data transfer rates, range, and other features of the wireless network.

Channel and Frequency: Access points operate on specific channels and frequencies. In areas with multiple access points, it’s important to choose a channel and frequency that is not being used by other access points to avoid interference.

SSID and Security: Access points broadcast a Service Set Identifier (SSID), which is the name of the wireless network. Access points also support different security protocols, such as Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), and WPA2, to ensure that only authorized users can connect to the network.

Antennas: Access points have antennas that transmit and receive wireless signals. The number and type of antennas can affect the range and performance of the wireless network.

Power over Ethernet (PoE): Some access points support Power over Ethernet (PoE), which allows them to receive power and data over the same Ethernet cable. This can simplify installation and reduce the number of cables needed.

Mesh Networking: Some access points support mesh networking, which allows multiple access points to work together to create a single wireless network. This can extend the range of the network and improve coverage in areas with weak signals.

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24
Q

Compare and contrast common networking hardware for patch panels.

A

Definition: A patch panel is a device that provides a central location for terminating network cables and connecting them to network devices. Patch panels are commonly used in data centers and server rooms to organize and manage network cables.

Types of Patch Panels: There are two main types of patch panels: punch-down and modular. Punch-down patch panels require the wires to be punched down into the panel with a special tool. Modular patch panels use pre-terminated cables that snap into place.

Port Density: Patch panels come in different port densities, which determines the number of connections that can be made. The most common port densities are 24 and 48 ports.

Wiring Standards: Patch panels support different wiring standards, such as T568A and T568B, which determine the order of the wires in the Ethernet cable. It’s important to use the same wiring standard for the patch panel and all network devices to ensure proper connectivity.

Cable Management: Patch panels often include cable management features, such as cable ties and loops, to help organize and secure the cables. Proper cable management can help reduce cable clutter and make it easier to trace cables when troubleshooting.

Labeling: Patch panels should be labeled to identify the ports and cables. This can help simplify troubleshooting and make it easier to identify the correct cable when making changes or additions to the network.

Compatibility: Patch panels should be compatible with the network devices they are connecting to, such as switches, routers, and servers. It’s important to choose a patch panel that supports the same network speed and technology as the connected devices to ensure optimal performance.

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25
Q

Compare and contrast common networking hardware for firewalls.

A

Definition: A firewall is a network security device that monitors and controls incoming and outgoing network traffic. Firewalls are designed to prevent unauthorized access to or from a network.

Types of Firewalls: There are several types of firewalls, including hardware and software-based firewalls. Hardware firewalls are standalone devices that are installed between the network and the internet. Software-based firewalls are installed on individual computers or servers and provide protection for that device only.

Firewall Rules: Firewalls are configured with rules that determine what traffic is allowed to pass through the firewall and what traffic is blocked. These rules can be based on the source and destination IP addresses, ports, protocols, and application type.

Stateful vs. Stateless Firewalls: Stateful firewalls keep track of the state of network connections and can make decisions based on the context of the traffic. Stateless firewalls do not keep track of the state of network connections and make decisions based on individual packets.

Network Zones: Firewalls often divide networks into different zones, such as a DMZ (demilitarized zone) and an internal network. The DMZ is a separate network that provides controlled access to services that are accessible from the internet, while the internal network is restricted to authorized users and devices.

Intrusion Detection and Prevention: Some firewalls include intrusion detection and prevention capabilities, which can detect and block suspicious network traffic and prevent attacks.

VPN Support: Some firewalls include VPN (virtual private network) support, which allows remote users to securely access the network over the internet.

Unified Threat Management: Some firewalls offer unified threat management (UTM) capabilities, which combine multiple security functions into a single device, such as antivirus, antispam, and web filtering.

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26
Q

Compare and contrast common networking hardware for PoE injectors.

A

Definition: Power over Ethernet (PoE) injectors are devices that allow Ethernet-enabled devices to receive power and data over the same cable. PoE injectors are often used to power wireless access points, IP cameras, and other network devices that do not have built-in power supplies.

PoE Standards: There are several PoE standards, including 802.3af, 802.3at, and 802.3bt. The different standards provide varying levels of power to connected devices.

Power Output: PoE injectors can provide power ranging from 15.4 watts to 90 watts, depending on the standard and the device being powered.

PoE Compatibility: Not all devices are PoE-compatible, and some devices may require additional adapters or equipment to be used with PoE injectors.

PoE Injector Placement: PoE injectors should be placed close to the device being powered to minimize power loss over the Ethernet cable.

PoE Injector Safety: PoE injectors should be used with caution and should be kept away from water, heat sources, and other potential hazards.

PoE Injector Troubleshooting: If a PoE-enabled device is not receiving power, check the connections between the device and the PoE injector, as well as the power source for the PoE injector itself.

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27
Q

Compare and contrast common networking hardware for PoE switches.

A

Definition: Power over Ethernet (PoE) switches are network switches that provide power and data over the same cable to connected devices. PoE switches are often used to power devices such as wireless access points, IP cameras, and VoIP phones.

PoE Standards: There are several PoE standards, including 802.3af, 802.3at, and 802.3bt. The different standards provide varying levels of power to connected devices.

Power Output: PoE switches can provide power ranging from 15.4 watts to 90 watts per port, depending on the standard and the device being powered.

PoE Compatibility: Not all devices are PoE-compatible, and some devices may require additional adapters or equipment to be used with PoE switches.

PoE Switch Placement: PoE switches should be placed close to the device being powered to minimize power loss over the Ethernet cable.

PoE Switch Safety: PoE switches should be used with caution and should be kept away from water, heat sources, and other potential hazards.

PoE Switch Troubleshooting: If a PoE-enabled device is not receiving power, check the connections between the device and the PoE switch, as well as the power source for the PoE switch itself.

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28
Q

Compare and contrast common networking hardware for PoE standards.

A

Definition: Power over Ethernet (PoE) is a technology that allows network cables to carry electrical power, which is used to power connected devices such as wireless access points, IP cameras, and VoIP phones.

PoE Standards: There are several PoE standards, including 802.3af, 802.3at, and 802.3bt. The different standards provide varying levels of power to connected devices.

802.3af: This PoE standard provides up to 15.4 watts of power per port, which is suitable for many devices such as IP phones, wireless access points, and IP cameras.

802.3at: This PoE standard, also known as PoE+, provides up to 30 watts of power per port, which is suitable for high-power devices such as pan-tilt-zoom (PTZ) cameras and access points with multiple radios.

802.3bt: This PoE standard, also known as PoE++, provides up to 60 watts or even 90 watts of power per port, which is suitable for devices that require high levels of power such as LED lighting, video conferencing systems, and virtual desktop infrastructure (VDI) endpoints.

PoE Compatibility: Not all devices are PoE-compatible, and some devices may require additional adapters or equipment to be used with PoE switches.

PoE Switch Placement: PoE switches should be placed close to the device being powered to minimize power loss over the Ethernet cable.

PoE Switch Safety: PoE switches should be used with caution and should be kept away from water, heat sources, and other potential hazards.

PoE Switch Troubleshooting: If a PoE-enabled device is not receiving power, check the connections between the device and the PoE switch, as well as the power source for the PoE switch itself.

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29
Q

Compare and contrast common networking hardware for hubs.

A

Definition: A hub is a network device that allows multiple devices to connect and communicate with each other on a network.

Function: A hub operates by receiving incoming data packets and forwarding them to all other connected devices.

Types: There are two main types of hubs: active (powered) and passive (unpowered). Active hubs amplify the signal of incoming data packets, while passive hubs do not.

Speed: Hubs are typically available in 10/100 Mbps or 10/100/1000 Mbps (Gigabit) speed configurations.

Limitations: Hubs have several limitations, including limited bandwidth, increased network latency, and a lack of network security features.

Advantages: Hubs are typically inexpensive and easy to install.

Disadvantages: Hubs are largely outdated and have been replaced by more advanced network devices such as switches and routers.

Recommendation: When setting up a network, it is recommended to use a switch instead of a hub, as switches provide greater network efficiency and security.

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30
Q

Compare and contrast common networking hardware for cable modems.

A

Definition: A cable modem is a networking device that allows users to connect to the internet using a cable television network.

Function: A cable modem receives digital data from the internet service provider (ISP) over the cable TV network and translates it into a form that can be used by a computer or other device.

Types: There are several types of cable modems, including standalone modems and combination modem/router devices.

Speed: Cable modems are typically available in several speed configurations, ranging from basic 10/100 Mbps to high-speed gigabit (1 Gbps) connections.

Compatibility: When purchasing a cable modem, it is important to ensure that it is compatible with the internet service provider and the type of cable network being used.

Installation: Cable modems are typically installed by the ISP or by the user, depending on the specific circumstances.

Advantages: Cable modems offer fast and reliable internet connectivity over a cable TV network, with the ability to support multiple devices.

Disadvantages: Cable modem performance can be impacted by network congestion, and some ISPs have bandwidth caps or may throttle data transfer speeds.

Recommendation: When setting up a home network, it is recommended to use a combination modem/router device to provide both internet connectivity and local network connectivity.

31
Q

Compare and contrast common networking hardware for DSL.

A

Definition: DSL (Digital Subscriber Line) is a type of internet connection that uses existing telephone lines to provide high-speed internet access.

Function: DSL technology allows data to be transmitted over telephone lines in a way that does not interfere with voice calls.

Types: There are several types of DSL, including ADSL, SDSL, and VDSL, each with different data transfer rates and other characteristics.

Speed: DSL speeds can vary widely depending on the type of DSL and the distance between the user’s location and the telephone company’s central office.

Equipment: DSL requires special equipment to be installed at both the user’s location (a DSL modem) and the telephone company’s central office (a DSLAM or DSL access multiplexer).

Compatibility: When purchasing a DSL modem, it is important to ensure that it is compatible with the user’s internet service provider and the type of DSL being used.

Installation: DSL modems can be self-installed by users or installed by the ISP or a professional technician, depending on the specific circumstances.

Advantages: DSL provides an always-on internet connection that does not require a phone line to be tied up, and can often provide faster speeds than dial-up connections.

Disadvantages: DSL speeds can be affected by distance from the central office, line quality, and other factors, and can be slower than other types of high-speed internet connections like cable or fibre optic.

Recommendation: DSL may be a good option for users in areas where cable or fibre optic internet is not available or where high-speed internet is required but the cost is a concern.

32
Q

Compare and contrast common networking hardware for ONT.

A

Definition: An ONT (Optical Network Terminal) is a device used in fibre optic networks to convert optical signals into electrical signals that can be used by devices such as computers, phones, and TVs.

Function: The ONT serves as the interface between the fibre optic network and the user’s devices, allowing the user to access high-speed internet, voice, and video services.

Location: The ONT is typically located inside or outside the user’s home or business, depending on the type of network and the service provider.

Equipment: The ONT typically includes several ports for connecting devices, as well as power and status indicators to indicate connectivity and signal strength.

Compatibility: When purchasing an ONT, it is important to ensure that it is compatible with the user’s fibre optic network and the service provider.

Installation: The ONT is typically installed by the service provider or a professional technician, and may require the installation of additional equipment such as a fibre optic cable or a power supply.

Advantages: The use of fibre optic networks and ONT devices allows for much faster data transfer speeds than traditional copper wire networks, and can support a wide range of high-bandwidth applications such as video streaming, online gaming, and cloud computing.

Disadvantages: The cost of fibre optic networks and ONT devices can be higher than traditional copper wire networks, and may not be available in all areas.

Recommendation: If high-speed internet access is a priority, a fibre optic network with an ONT device may be a good option for users who have access to the technology and are willing to pay the additional cost.

33
Q

Compare and contrast common networking hardware for NIC.

A

Definition: A NIC (Network Interface Card) is a hardware component that enables a computer to connect to a network.

Function: The NIC provides a physical connection between the computer and the network, allowing the computer to send and receive data over the network.

Types: There are several types of NICs, including Ethernet NICs, wireless NICs, and fibre optic NICs.

Installation: NICs can be installed internally in a computer or externally through a USB port. Installation typically involves opening the computer case, locating an available expansion slot, and inserting the NIC card.

Configuration: Once the NIC is installed, it may require configuration through the computer’s operating system or through software provided by the NIC manufacturer.

Compatibility: When purchasing a NIC, it is important to ensure that it is compatible with the computer’s operating system and with the type of network the computer will be connecting to.

Advantages: A NIC enables a computer to connect to a network, providing access to shared resources such as printers, files, and applications. It also enables the computer to access the internet and other network-based services.

Disadvantages: A faulty or improperly configured NIC can cause network connectivity issues and slow down network performance. NICs may also be vulnerable to security threats if not properly secured.

Recommendation: A properly installed and configured NIC is essential for accessing networks and network-based services. When purchasing a NIC, it is important to select a device that is compatible with the computer’s operating system and the type of network it will be connecting to, and to follow proper installation and configuration procedures to ensure optimal performance and security.

34
Q

Compare and contrast common networking hardware for SDN.

A

Definition: SDN is a networking architecture that separates the network control plane from the forwarding plane, enabling the network to be managed and controlled through software.

Function: SDN provides a centralized, programmable network that can be managed and controlled through software, rather than through traditional hardware-based methods.

Components: An SDN architecture typically consists of three main components: the SDN controller, which provides centralized control and management of the network; the network devices, which forward traffic based on instructions from the controller; and the application layer, which provides the software applications that interact with the network.

Benefits: SDN enables greater network agility and flexibility, allowing for more efficient network management and faster deployment of new services and applications. It also provides greater visibility and control over network traffic and enables more advanced network security and management capabilities.

Challenges: SDN requires a high level of network expertise and specialized skills to implement and manage effectively. It also requires careful planning and consideration of the network infrastructure and application requirements, as well as potential security implications.

Use cases: SDN is commonly used in data centre environments to enable greater network flexibility and agility, and in software-defined WAN (SD-WAN) solutions to provide greater control and visibility over wide area networks.

Standards: SDN is based on several industry standards, including OpenFlow, which defines the communication protocol between the controller and network devices, and the Open Networking Foundation (ONF), which provides guidance and support for SDN implementation and management.

Future trends: SDN is expected to continue to evolve and become more widely adopted, particularly as more organizations move towards cloud-based and software-defined infrastructure models. However, the complexity and specialized skills required for effective SDN implementation and management may continue to present challenges for some organizations.

35
Q

Frequencies: 2.4GHz.

A

The 2.4GHz frequency band is a popular frequency for wireless communication, particularly for Wi-Fi networks.

The 2.4GHz frequency band is divided into 14 channels, each with a bandwidth of 22MHz.

However, due to overlapping channels and other factors, only three non-overlapping channels (1, 6, and 11) should be used for Wi-Fi networks.

The protocols commonly used on the 2.4GHz frequency band for Wi-Fi networks include 802.11b, 802.11g, and 802.11n.

These protocols have different data rates and use different modulation schemes, but are all compatible with each other.

802.11b is an older protocol that operates at a maximum data rate of 11Mbps. It uses Direct-Sequence Spread Spectrum (DSSS) modulation.

802.11g is a newer protocol that operates at a maximum data rate of 54Mbps. It uses Orthogonal Frequency-Division Multiplexing (OFDM) modulation, which is more efficient than DSSS.

802.11n is the most recent protocol and operates at a maximum data rate of 600Mbps.

It uses Multiple-Input Multiple-Output (MIMO) technology, which allows for multiple data streams to be transmitted simultaneously.

When comparing and contrasting these protocols, it’s important to understand their differences in terms of data rates, range, and compatibility.

For example, 802.11b has a lower data rate and shorter range than 802.11g and 802.11n, but is still compatible with these protocols.

802.11n has the highest data rate and longest range, but may not be compatible with older devices that only support 802.11b or 802.11g.

In summary, for the CompTIA 1101 exam, you should have a good understanding of the 2.4GHz frequency band, the channels used on this band, and the protocols commonly used for wireless communication on this band, including their data rates, modulation schemes, and compatibility.

Wireless routers use either the 2.4GHz band or the 5GHz band.

Each band offers advantages and
disadvantages.

The 2.4GHz band has a longer range but can perform at slower speeds.

The 5GHz band can provide faster rates but has a shorter range. A couple of reasons account for the differences.

First, lower frequencies travel better through obstacles such as floors and walls.

Second, the 5GHz band is less used and has more channels than the 2.4GHz band, and its channels do not overlap.

This means that 5GHz devices do not contend with other devices for bandwidth, as do devices in
the more popular 2.4GHz range.

2.4GHz:

  • 50m (160
    feet) indoors

Channels: 11

Advantages: Longer range

Disadvantages: Slower performance, channels easily overlap.

36
Q

Frequencies: 5GHz

A

5GHz:

  • 15m (50 feet)
    indoors

Channels: 23

Benefits: Faster performance,
channels do not overlap

Cons: Shorter range

The 5GHz frequency band is a newer and less crowded frequency for wireless communication compared to the 2.4GHz frequency band.

The 5GHz frequency band is divided into many more channels than the 2.4GHz band, with up to 25 non-overlapping channels available in some countries.

The protocols commonly used on the 5GHz frequency band for Wi-Fi networks include 802.11a, 802.11n, 802.11ac, and 802.11ax (also known as Wi-Fi 6).

These protocols have different data rates and use different modulation schemes, but are all compatible with each other.

802.11a is an older protocol that operates at a maximum data rate of 54Mbps. It uses OFDM modulation, similar to 802.11g.

802.11n and 802.11ac are newer protocols that use MIMO technology and can operate at much higher data rates than 802.11a or 802.11g. 802.11n can operate at a maximum data rate of 600Mbps, while 802.11ac can operate at a maximum data rate of several gigabits per second.

802.11ax (Wi-Fi 6) is the most recent protocol and operates at a maximum data rate of several gigabits per second.

It uses advanced technologies such as MU-MIMO (Multi-User Multiple Input Multiple Output), OFDMA (Orthogonal Frequency Division Multiple Access), and spatial reuse to improve performance in high-density environments.

When comparing and contrasting these protocols, you should focus on their data rates, range, compatibility, and specific technologies used.

For example, 802.11a has a lower data rate and shorter range than 802.11n or 802.11ac, but operates on a less crowded frequency band. 802.11ac has a higher data rate and longer range than 802.11n, but may not be compatible with older devices that only support 802.11a or 802.11n.

Wi-Fi 6 (802.11ax) is the most advanced protocol and offers the highest data rate and improved performance in high-density environments.

In summary, for the CompTIA 1101 exam, you should have a good understanding of the 5GHz frequency band, the channels used on this band, and the protocols commonly used for wireless communication on this band, including their data rates, modulation schemes, and compatibility.

37
Q

Channels: regulations

A

Installing a router involves selecting an appropriate channel for the signal. For best
results, avoid overlapping channels.

Only channels 1, 6, and 11 do not overlap with other
channels, so it is best to use one of these three channels.

Some routers feature an Auto setting that enables the router to use the least-active channel, but if
you prefer to (or must) select a channel manually, use a Wi-Fi diagnostic utility (discussed later in
this chapter) to find the least-used channel.

The 2.4GHz frequency band is divided into 14 channels, but in many countries, only channels 1 through 11 are allowed to be used for Wi-Fi networks.

This is because channels 12 through 14 may interfere with other wireless systems such as satellite communication.

The 5GHz frequency band has many more channels than the 2.4GHz band, with up to 25 non-overlapping channels available in some countries.

However, the exact number of channels available and the regulations surrounding their use may vary depending on your country or region.

In some cases, certain channels may only be available for indoor use or for certain types of Wi-Fi networks.

In general, when setting up a Wi-Fi network, you should choose a channel that is not already in use by other nearby networks, as this can cause interference and degrade performance.

Wi-Fi routers and access points often have a feature called “auto channel selection” that can automatically choose the best channel based on local conditions.
It’s also important to note that some Wi-Fi protocols, such as 802.11n and 802.11ac, may require wider channel widths in order to achieve their maximum data rates.

For example, 802.11n can use channel widths of 20MHz or 40MHz, while 802.11ac can use channel widths of 20MHz, 40MHz, or 80MHz. However, using wider channel widths may also increase the risk of interference with other networks.

Additionally, in some countries, there may be additional regulations or restrictions on the use of certain frequencies or channels.

For example, in the United States, the Federal Communications Commission (FCC) has regulations surrounding the use of certain frequency bands and transmission power levels for Wi-Fi networks.
When studying for the CompTIA 1101 exam, be sure to familiarize yourself with the specific channel regulations and guidelines for your country or region, as well as the best practices for choosing and configuring channels for optimal Wi-Fi performance.

38
Q

Wireless networking compare and contrast protocols: Bluetooth

A

Bluetooth classes:

Class Power Range
Class 1 100mW 100m (328 ft)
Class 2 2.5mW 10m (33 ft)
Class 3 1mW 1m (3 ft)

Bluetooth is a wireless network technology that was primarily designed to operate in peer-to-peer mode between PCs and other devices, such as printers, projectors, smartphones, mouse devices, and keyboards.

It uses the same 2.4GHz frequency as wireless networks but uses a spread-spectrum frequency-hopping signalling method to minimize interference. Bluetooth devices connect to each other to form a personal area network (PAN).

Bluetooth versions offer different data transfer rates, with version 1.2 offering a transfer rate of 1Mbps and version 2 offering 3Mbps. Version 3.0 + HS can reach speeds of up to 24Mbps, and it uses

Bluetooth only to establish the connection, with the actual data transfer happening over an 802.11 link. This feature is known as Alternative MAC/PHY (AMP). Bluetooth 4.0, also known as Bluetooth Low Energy, is designed for use with very low-power applications, such as sensors. Bluetooth 4.1 enables Bluetooth to perform multiple roles at the same time and to work better with LTE and 5G cellular devices.

Bluetooth 4.2 includes additional features to support the Internet of Things (IoT), and Bluetooth 5.0 was designed with the IoT in mind.

IoT devices can be spread around a home, factory, or farm and can send a day’s worth of stored data back to a network. Bluetooth 5 can provide up to twice the speed and up to four times the range of Bluetooth 4, while keeping power consumption low.

As IoT growth continues at a rapid rate, Bluetooth 5 is a common solution for IoT gateway devices. Some systems and devices include integrated Bluetooth adapters, while others need a Bluetooth module connected to a USB port to enable Bluetooth networking.

Interference: Bluetooth uses a spread-spectrum frequency-hopping signaling method to minimize interference from other wireless networks operating in the same frequency range. However, interference can still occur if there are too many devices operating in the same area.

39
Q

Bluetooth versions

A

1.2 1 Mbps 10 meters (33 feet) Basic data transfer, adaptive frequency hopping

2.0 + EDR 3 Mbps 10 meters (33 feet) Enhanced data rate (EDR), faster pairing, lower power consumption

2.1 + EDR 3 Mbps 100 meters (328 feet) Secure simple pairing (SSP), extended inquiry response (EIR), better power management

3.0 + HS 24 Mbps 100 meters (328 feet) Alternative MAC/PHY (AMP), faster data transfer

4.0 (BLE) 1 Mbps 50 meters (164 feet) Bluetooth Low Energy (BLE), low power consumption

4.1 1-2 Mbps 100 meters (328 feet) Dual-mode topology, better coexistence with LTE and Wi-Fi

4.2 1-2 Mbps 100 meters (328 feet) Internet of Things (IoT) support, improved security, faster pairing

5.0 2 Mbps 200 meters (656 feet) Increased data transfer speed, longer range, improved advertising, and data exchange, low power consumption

40
Q

802.11a,b,g,n,ac,ax capabilities

A

Standard, Frequency, Maximum Data Rate, Maximum Range, Modulation, Bandwidth

802.11a 5 GHz 54 Mbps 35 meters (115 feet) OFDM 20 MHz

802.11b 2.4 GHz 11 Mbps 38 meters (125 feet) DSSS 22 MHz

802.11g 2.4 GHz 54 Mbps 38 meters (125 feet) OFDM/DSSS 20 MHz

802.11n 2.4 GHz/5 GHz 600 Mbps 70 meters (230 feet) OFDM 20/40 MHz

802.11ac 5 GHz 6.9 Gbps 35 meters (115 feet) OFDM 20/40/80/160 MHz

802.11ax 2.4 GHz/5 GHz 10 Gbps 35 meters (115 feet) OFDMA 20/40/80/160 MHz

Six Wi-Fi standards are in use:

802.11b has a maximum speed of 11Mbps and can fall back to 5.5Mbps or slower, if
necessary. It uses the 2.4GHz frequency band with 20MHz-wide channels.

802.11a has a maximum speed of 54Mbps and supports slower speeds, from 6Mbps to
48Mbps, as needed. It uses the 5GHz frequency band.

802.11g has a maximum speed of 54Mbps and supports slower speeds, from 6Mbps to
48Mbps, as needed.

Unlike 802.11a, 802.11g uses the 2.4GHz frequency band, so it is
backward compatible with 802.11b.

802.11n (Wi-Fi 4) has a maximum speed of 150Mbps when using a single 20MHz channel,
or it can run at up to 300Mbps with channel bonding (40MHz channel).

All 802.11n devices
use the 2.4GHz frequency by default, but 802.11n can optionally support 5GHz frequencies
as well.

802.11n supports MIMO (multiple input multiple output) antennas to improve
performance and range, although not all devices include multiple antennas.

802.11ac (Wi-Fi 5) uses only the 5GHz band and supports up to 80MHz-wide channels,
compared to 20MHz for 802.11b/g and 40MHz for 802.11n using channel bonding.

It supports multiuser MIMO (MU-MIMO). The speed of 802.11ac is up to 433Mbps per
stream when 80MHz-wide channels are used.

802.11ax (Wi-Fi 6 & Wi-Fi 6E) has important improvements over Wi-Fi 5 and others. Wi-Fi
6 uses both 2.4GHz and 5 GHz bands, with increased speeds up to 9.6Gbps.

Wi-Fi 6E
improves upon Wi-Fi 6 by supporting the 6GHz band. Benefits include increased capacity,
with up to seven channels at 160MHz wide, better performance, and improved power
efficiency

41
Q

Long range fixed wireless: licensing

A

Cable modems and DSL have been the traditional method for homes and businesses to connect to
the Internet.

In cases where physical access to an ISP was not possible, such as rural areas, satellite access has been an option, although it is a slower, less reliable, and more expensive
solution.

In recent years, another option has emerged: fixed wireless Internet.

Fixed wireless providers send a signal from a wireless tower to customers who have a small
antenna in their homes or business. For best results, the antenna is placed in direct line of sight to
the tower, sometimes aimed out a window or mounted on a rooftop.

The antenna is connected via
a cable to a router for wired and wireless access to the home or office.

Data rates can be very fast and the service is competitive with wired access, although the ISP
usually sets the data rate to coincide with the customer’s subscription rate.

In the UK, fixed wireless systems operating in the frequency bands used for long-range transmission (such as the 5.8 GHz band) require a license from Ofcom, the UK’s communications regulator.

Ofcom issues licenses for fixed wireless systems on a case-by-case basis, taking into account factors such as the location and power output of the equipment, the potential for interference with other services, and compliance with relevant technical standards.

To obtain a license, applicants must submit an application to Ofcom and pay the appropriate fee. Once the license is granted, licensees must comply with the conditions of the license and any applicable regulations, such as those relating to equipment standards and emissions limits.

It’s important to note that licensing requirements may vary depending on the specific circumstances, so it’s always a good idea to check with Ofcom or a qualified professional for guidance on licensing for a specific wireless system.

42
Q

Long-range fixed wireless: unlicensed

A

Unlicensed long-range fixed wireless refers to the use of wireless technologies, such as Wi-Fi, to provide point-to-point or point-to-multipoint connections over long distances without the need for a license. Unlike licensed wireless, unlicensed wireless can be used freely by anyone without obtaining permission from regulatory authorities.

One common unlicensed long-range fixed wireless technology is Wi-Fi, which operates in the unlicensed 2.4GHz and 5GHz frequency bands. Wi-Fi signals can travel for several miles over open terrain using high-gain antennas and other techniques to boost signal strength.

Another technology used for unlicensed long-range fixed wireless is the use of unlicensed wireless broadband radios, such as those using the 900MHz, 2.4GHz, 3.65GHz, and 5.8GHz frequency bands. These radios are often used by Internet service providers (ISPs) to provide high-speed internet connections to remote areas where traditional wired connections are not available.

It’s important to note that while unlicensed wireless can be used freely, there are still rules and regulations in place to ensure that it does not interfere with licensed services or cause harm to public safety. It’s essential to research and follow the applicable regulations in your region before setting up an unlicensed long-range fixed wireless network.

Unlicensed long range fixed wireless is allowed to be unlicensed because it operates in frequency bands that are not typically used by other wireless services, such as television and cellular networks.

Additionally, the power levels used in unlicensed long range fixed wireless are typically much lower than those used in licensed services, which helps minimize the potential for interference with other wireless services. Unlicensed long range fixed wireless can also provide an affordable and flexible solution for businesses and organizations that need to establish high-speed data connections over long distances. However, it is important to note that unlicensed wireless networks may be more susceptible to interference and security risks, so appropriate measures should be taken to mitigate these issues.

43
Q

Long range fixed wireless: power and regulatory requirements for wireless power

A

Wireless power transfer (WPT) is the process of using electric power to wirelessly charge a
device.

Two categories of WPT exist near field and far field. Much like it sounds, near-field transfers power over short distances, such as charging an electric toothbrush or using a wireless charging pad for a smartphone.

Far-field transfers power over longer distances and has potential application in powering unmanned aircraft and vehicles or solar-powered satellites

900 MHz Up to 4 watts
2.4 GHz Up to 4 watts
5.8 GHz Up to 4 watts
24 GHz Up to 250 watts
60 GHz Up to 40 watts

44
Q

NFC: wireless networking

A

Near-field communication (NFC) is a feature included in many mobile devices such as
smartphones and tablets for data transfer and shopping. When NFC is enabled and a suitable
payment system (such as Apple Pay or Google Pay) is installed on a mobile device, the device can
be used for secure payments at any retailer that supports NFC payments.

NFC can also be used to automatically turn on Bluetooth and transfer files between devices (a feature sometimes referred to as “tap and go” or, on Android devices, Android Beam).

It can be enabled separately from NFC for payments. Apple uses NFC for purchases and other limited
functions that require secure data. The technology is widely used and continues to proliferate as
the world moves toward contactless transactions.
RFID

NFC stands for Near Field Communication, which is a short-range wireless communication technology that allows devices to communicate with each other when they are brought within a few centimeters of each other. It operates at a frequency of 13.56 MHz and has a maximum communication range of about 4 centimetres.

NFC is often used for contactless payment systems, such as mobile payments, and for reading information from RFID tags. It is also used for data transfer between two NFC-enabled devices, such as smartphones and tablets.

NFC can operate in two modes: active and passive. In active mode, both devices generate their own magnetic fields and exchange data. In passive mode, one device generates the magnetic field and the other device uses that field to generate a small amount of power and communicate with the first device.

NFC is considered to be a secure technology because it requires physical proximity for communication to take place. It also has a low data transfer rate of up to 424 kbps, which makes it unsuitable for large data transfers. However, it is ideal for small data transfers and for applications that require quick and secure communication between two devices in close proximity.

45
Q

RFID - radio-frequency identification: wireless networking

A

Radio frequency identification (RFID) technology consists of an RFID tag that can broadcast
information about an item, as well as an RFID reader to accept the broadcast information and
deliver it to a computer system for use.

An example is RFID security badges that allow doors to
be unlocked in a secure environment, granting access to some while denying use to others.

In some retail environments, an item for sale has an RFID badge identifying the item’s name and
price. The badges on the items in a shopping cart broadcast their information to a checkout reader,
and customers can simply walk out the door with their purchases: The items are counted, priced,
and paid for just by passing the reader.

Passports and other identification documents might also
have RFID information embedded in them

RFID stands for Radio Frequency Identification, and it is a technology used for tracking and identifying objects using radio waves. RFID systems consist of a reader, an antenna, and a tag that is attached to the object being tracked.

The reader emits radio waves that are received by the tag, which responds with a unique identifier that is sent back to the reader. This allows the reader to identify and track the object that the tag is attached to.

RFID technology is used in a variety of applications, including inventory management, asset tracking, and access control. It is also used in contactless payment systems, such as credit cards and mobile payments.

RFID tags can be active or passive. Active tags have their own power source and can communicate with the reader over longer distances. Passive tags do not have their own power source and rely on the energy from the reader to communicate, which limits their range.

RFID operates at different frequency ranges, including low frequency (LF), high frequency (HF), and ultra-high frequency (UHF). LF RFID tags have a range of a few centimeters and are often used for access control systems. HF RFID tags have a range of up to a meter and are commonly used in inventory management. UHF RFID tags have a range of up to 12 meters and are used in applications such as supply chain management.

RFID technology has some security concerns, such as the potential for unauthorized access to personal information stored on RFID tags. However, security measures such as encryption can be implemented to mitigate these risks.

46
Q

Services provided by networked hosts: DNS

A

A Domain Name System (DNS) server has a database that contains public IP addresses and their associated domain names.

The purpose of a DNS server is to translate domain names used in web page requests into IP addresses.

DNS server functions are included in SOHO routers.

For larger networks, a separate DNS server can be used. A DNS server communicates with other, larger DNS servers if the requested addresses are not in its database.

DNS Name Resolution: DNS servers are responsible for resolving domain names to their corresponding IP addresses, enabling devices to locate resources on a network or the Internet. DNS servers maintain a database of domain names and IP addresses, and respond to DNS queries from clients to provide the correct IP address associated with a domain name.

DNS Zone Management: DNS servers manage DNS zones, which are portions of the DNS namespace that contain information about a specific domain or subdomain. DNS servers can create, modify, and delete DNS records within a zone, such as A records (mapping domain names to IP addresses), CNAME records (aliasing one domain name to another), MX records (specifying mail servers for a domain), and more.

DNS Caching: DNS servers can cache DNS records locally to improve the efficiency of DNS resolution. When a DNS server receives a query for a domain name, it first checks its local cache for the corresponding IP address. If the information is cached, the DNS server can respond immediately without having to query other DNS servers, reducing network traffic and improving response times.

DNS Forwarding: DNS servers can also be configured to forward DNS queries to other DNS servers if they do not have the requested domain name in their local cache. This allows DNS servers to collaborate and share DNS information, enabling efficient resolution of domain names across different parts of the Internet.

DNS Security: DNS servers can implement various security mechanisms to protect against DNS-related attacks, such as DNS spoofing, cache poisoning, and distributed denial of service (DDoS) attacks. This may include implementing DNSSEC (DNS Security Extensions) to add an additional layer of security to DNS queries and responses.

DNS Logging and Monitoring: DNS servers can generate logs and provide monitoring capabilities, allowing administrators to track DNS activity, troubleshoot issues, and monitor the health and performance of DNS services.

Overall, DNS server roles involve managing DNS name resolution, zone management, caching, forwarding, security, logging, and monitoring to ensure reliable and efficient DNS services within a network or across the Internet.

47
Q

Services provided by networked hosts: DHCP

A

A Domain Name System (DNS) server has a database that contains public IP addresses and their associated domain names.

The purpose of a DNS server is to translate domain names used in web page requests into IP addresses.

DNS server functions are included in SOHO routers. For larger
networks, a separate DNS server can be used.

A DNS server communicates with other, larger DNS servers if the requested addresses are not in its database.

Automatic IP address configuration

Available on most routers

Usually running on DHCP servers

IP Address Management: DHCP servers automatically assign and manage IP addresses to client devices on a network. DHCP eliminates the need for manual IP address configuration, making it more efficient to manage IP addresses in large networks.

Dynamic IP Address Allocation: DHCP servers provide dynamic IP address allocation, which allows IP addresses to be leased to client devices for a specific period of time. This enables efficient utilization of IP addresses by reusing them when they are not in use, preventing IP address exhaustion.

IP Configuration Information: DHCP servers can also provide additional IP configuration information to client devices, such as subnet mask, default gateway, and DNS server addresses. This simplifies network configuration for clients and ensures consistency in network settings.

IP Address Reservation: DHCP servers can reserve specific IP addresses for certain devices based on their MAC addresses. This allows for consistent IP address assignment to specific devices, such as servers or printers, ensuring that they always receive the same IP address.

Centralized Management: DHCP servers provide centralized management of IP address allocation and configuration, making it easier to manage and update IP address settings across a network. This eliminates the need for manual IP address configuration on individual devices.

Monitoring and Logging: DHCP servers can generate logs and provide monitoring capabilities to track IP address allocation, detect and troubleshoot issues, and monitor the health and performance of DHCP services.

Understanding these key services provided by DHCP servers, including IP address management, dynamic IP address allocation, IP configuration information, IP address reservation, centralized management, and monitoring/logging, should help you prepare for questions related to DHCP on the CompTIA 1101 exam.

48
Q

Services provided by networked hosts: Fileshare

A

A file server is used to provide shared storage on a network. A file server is typically a computer
with a single large drive or a RAID array for storage.

Dedicated servers are used only for storage; a computer that shares storage and also performs standalone tasks (as in a Windows workgroup
with 10 or fewer systems) is known as a nondedicated server.

A network-attached storage (NAS) device is a special kind of file server designed to store large
amounts of data in a central location for users on the network.

A NAS is essentially one or more
drives fitted with an Ethernet connection; it is assigned its own IP address.

Fileshare is a specialized data server system that allows for efficient processing of files that many users across a network access at one time.

File Storage: File sharing servers provide a centralized location for storing files that can be accessed by authorized users over the network, allowing for efficient file organization, management, and access control.

File Access Control: File sharing servers allow administrators to set permissions and access controls on files and folders, ensuring that only authorized users can access, modify, or delete files based on their permissions.

File Collaboration: File sharing servers enable multiple users to collaborate on files, allowing for concurrent access, editing, and versioning of files, which promotes teamwork and productivity.

File Transfer: File sharing servers facilitate the transfer of files between users on the network, allowing for efficient and secure file exchange without the need for physical media.

File Backup and Recovery: File sharing servers often provide built-in backup and recovery mechanisms to protect against data loss and facilitate file restoration in case of accidental deletion or system failure.

File Auditing and Monitoring: File sharing servers may offer auditing and monitoring features to track file access, changes, and other activities for security, compliance, and troubleshooting purposes.

Understanding these key services provided by file sharing servers, including file storage, file access control, file collaboration, file transfer, file backup and recovery, and file auditing and monitoring, should help you prepare for questions related to file sharing on the CompTIA 1101 exam.

49
Q

Services provided by networked hosts: Print servers

A

A print server manages the printing tasks for multiple users who share one or more printers in an office.

Printing a document in a large office was once a complicated task because printers were expensive and access to them was limited.

Eventually, a designated computer and printer became
hosts on an office network, and managing printing tasks for the whole office became more
efficient.

Because print jobs might be requested faster than a printer can deliver them, print
servers queue print jobs and deliver them to appropriate printers when they are available.

They can also track the usage of printers on the network. Print servers and printers can be either wired or wireless.

Connect a printer to the network

May be software in a computer

May be built-in printer

Uses Standard printing protocols
- SMB. IPP (internet printing protocol, LPD (Line Printer Daemon)

Print Queue Management: Print servers manage print queues, which hold print jobs from users until they are processed and printed by the printer. Print servers handle print job prioritization, scheduling, and spooling to ensure efficient printing.

Printer Driver Management: Print servers store and manage printer drivers, which are software that allows client devices to communicate with printers. Print servers provide the correct printer drivers to clients, ensuring compatibility and reliable printing.

Printer Access Control: Print servers allow administrators to set permissions and access controls on printers, determining which users or groups are allowed to print to specific printers. This helps control printer usage and prevent unauthorized printing.

Printer Monitoring: Print servers provide monitoring capabilities to track printer status, usage, and error messages. This helps administrators troubleshoot printer issues, identify printer consumables that need replacement, and monitor printer performance.

Printer Queue Administration: Print servers enable administrators to manage print queues, such as pausing, resuming, cancelling, or prioritizing print jobs. This allows for efficient print job management and ensures smooth printing operations.

Printer Accounting and Reporting: Print servers may offer accounting and reporting features to track printer usage, print job costs, and generate usage reports for billing, cost allocation, or budgeting purposes.

Understanding these key services provided by print servers, including print queue management, printer driver management, printer access control, printer monitoring, printer queue administration, and printer accounting and reporting, should help you prepare for questions related to print servers on the CompTIA 1101 exam.

50
Q

Services provided by networked hosts: Mail servers

A

A mail server sends or receives email on a network. An SMTP (Simple Mail Transfer Protocol)
server is used to send outgoing email, and either a POP3 (Post Office Protocol version 3) or IMAP
(Internet Message Access Protocol) server is used to receive mail.

Mail server platforms are
available from many vendors. For example, Microsoft Exchange Server is a popular mail server
platform that includes email, contacts, calendar, scheduling, and more.

Email Storage and Retrieval: Mail servers store and manage email messages, allowing users to send, receive, and store emails. Mail servers provide email storage and retrieval functionality, including mailbox management, message routing, and email queuing.

Email Access Protocol Support: Mail servers support various email access protocols such as POP3 (Post Office Protocol 3), IMAP (Internet Message Access Protocol), and SMTP (Simple Mail Transfer Protocol) to enable clients to access and retrieve email messages from the server using email clients or webmail interfaces.

Email Address Management: Mail servers manage email addresses, domains, and user accounts, allowing for email address creation, deletion, and modification. Mail servers also handle email address routing, forwarding, and aliasing to ensure proper email delivery.

Store incoming mail

Send your outgoing mail

Usually managed by ISP or enterprise IT department (has requirements)

24/7 support

Email Authentication and Security: Mail servers provide authentication mechanisms such as SMTP authentication, SSL/TLS encryption, and spam filtering to protect against unauthorized access, email spoofing, and spam. Mail servers also handle virus scanning, email encryption, and other security measures to safeguard email communication.

Email Routing and Delivery: Mail servers handle email routing and delivery, including sending and receiving emails from other mail servers, managing email queues, and handling email delivery errors. Mail servers also provide message queuing, retrying, and bounce handling to ensure reliable email delivery.

Email Management and Administration: Mail servers offer management and administration features for email accounts, such as mailbox size limits, email forwarding, email aliases, and email archiving. Mail servers also provide logging, monitoring, and reporting capabilities for email usage, performance, and security.

Understanding these key services provided by mail servers, including email storage and retrieval, email access protocol support, email address management, email authentication and security, email routing and delivery, and email management and administration, should help you prepare for questions related to mail servers on the CompTIA 1101 exam.

51
Q

Services provided by networked hosts: Syslog

A

Syslog servers track and log events that happen on devices (such as routers, switches, and
firewalls) and printers on a network.

Devices on a network usually have a way to track their
system events, such as user logins and crashes, as well as other activities that the network
administrator has determined to be important.

The reports are sent to a central syslog server for
network managers to analyze, as needed.

Log Collection: Syslog servers collect logs from various network devices and systems, such as routers, switches, firewalls, servers, and applications. Logs contain valuable information about events, errors, and activities occurring on these devices, which can be used for troubleshooting, auditing, and monitoring purposes.

Log Aggregation and Centralization: Syslog servers aggregate logs from multiple sources into a central repository, providing a single location for storing, managing, and analyzing logs. This allows for centralized log management and makes it easier to search, filter, and analyze logs for identifying issues and detecting patterns.

Log Storage and Retention: Syslog servers store logs for a specified period, allowing for long-term retention and archival of logs. Syslog servers may also provide features for log compression, encryption, and backup to ensure data integrity and availability.

Log Parsing and Analysis: Syslog servers may parse logs to extract relevant information, such as timestamps, source IP addresses, error codes, and event descriptions. This enables log analysis and correlation to identify patterns, trends, and anomalies that may indicate security incidents, performance issues, or other concerns.

Alerting and Notification: Syslog servers may provide alerting and notification features to notify administrators or other stakeholders when specific events or conditions occur in logs. This helps in timely response to critical events and ensures proactive monitoring of the network and systems.

Log Monitoring and Reporting: Syslog servers may offer monitoring and reporting capabilities for log data, such as real-time monitoring of logs, generation of reports, and visualization of log data through dashboards. This provides insights into system behavior, performance, and security posture.

Understanding these key services provided by syslog servers, including log collection, log aggregation and centralization, log storage and retention, log parsing and analysis, alerting and notification, and log monitoring and reporting, should help you prepare for questions related to syslog on the CompTIA 1101 exam.

52
Q

Services provided by networked hosts: Web servers

A

Web servers are specialized computers that host websites and provide various types of content to
clients via the Internet.

A web server uses HTTPS to communicate with computers on other networks that are requesting information.

Web hosting is essential in business and education, and setting up a web server has been a common task for an IT professional for many years.

Today many companies use cloud-based web servers such as Amazon Web Services (AWS) Cloud, Microsoft Azure, and Google Cloud.

Web Content Delivery: Web servers deliver web content, including HTML, CSS, JavaScript, images, and other media files, to client devices such as web browsers. Web servers process client requests for web content and respond with the requested content, enabling users to access web pages and interact with web applications.

Web Application Support: Web servers support web applications by executing server-side scripts or programs, such as PHP, Python, Ruby, or ASP.NET, and generating dynamic content in response to client requests. Web servers may also interface with databases and other backend systems to retrieve and process data for web applications.

User Authentication and Authorization: Web servers may provide authentication and authorization mechanisms to secure access to web content and web applications. This includes verifying user credentials, managing user accounts, and enforcing access controls based on user roles, permissions, and other security policies.

Secure Communication: Web servers may provide support for SSL/TLS encryption, which secures communication between web servers and client devices, ensuring data confidentiality and integrity. This is important for protecting sensitive information, such as login credentials, credit card numbers, and other user data.

Web Server Logging and Monitoring: Web servers may generate logs that record information about web requests, errors, and other events for monitoring and troubleshooting purposes. Web servers may also provide monitoring features, such as performance metrics, error tracking, and real-time monitoring, to ensure optimal performance and availability of web services.

Load Balancing and Scalability: Web servers may be used in a load-balanced configuration to distribute incoming web requests across multiple web servers for improved performance, scalability, and fault tolerance. Load balancers distribute incoming requests based on various algorithms, such as round-robin, least connections, or session persistence.

Understanding these key services provided by web servers, including web content delivery, web application support, user authentication and authorization, secure communication, web server logging and monitoring, and load balancing and scalability, should help you prepare for questions related to web servers on the CompTIA 1101 exam.

Responds in browser requests
- Using standard browser protocols
- HTML, HTML5

Web Pages are stored on the server
- Download to the browser
- Static pages or built dynamically in real time

53
Q

Services provided by networked hosts: AAA

A

An AAA server is used to examine and then verify or deny credentials to a user who is attempting
to log into secured networks.

Usernames and permissions are stored in this central server, which
provides security certificates to users and records user logins to the network.

The authorization function of an AAA server refers to making sure users access only areas where
they have permission to go. After users are authenticated, their level of authorization is
determined and enforced.

The accounting function of an AAA server refers to keeping track of the resources and activities a
user has performed while on the network.

Accessing files and billing for services are examples of
accountable activities.

Authentication: AAA servers provide authentication services, which verify the identity of users or devices seeking access to a network or system. This may involve validating credentials, such as usernames and passwords, smart cards, biometrics, or other authentication factors, to ensure that only authorized users are granted access.

Authorization: AAA servers provide authorization services, which determine the level of access or privileges granted to authenticated users or devices based on their roles, permissions, and other policies. This includes defining and enforcing access controls, such as permissions to access certain resources, perform specific actions, or execute particular commands.

Accounting: AAA servers provide accounting services, which track and record usage information, such as user activities, resource utilization, and network traffic, for auditing, billing, and reporting purposes. This includes collecting and logging data related to user sessions, activities, and events, which can be used for monitoring, troubleshooting, and compliance requirements.

Centralized Policy Management: AAA servers may provide a centralized location for managing authentication, authorization, and accounting policies across the network or system. This allows for consistent policy enforcement, easy policy updates, and centralized reporting and auditing of policy compliance.

Integration with Other Network Services: AAA servers may integrate with other network services, such as VPNs (Virtual Private Networks), wireless networks, network switches, routers, and firewalls, to provide unified and centralized authentication, authorization, and accounting services. This simplifies network management, improves security, and ensures consistent policy enforcement across different network devices.

Understanding these key services provided by AAA servers, including authentication, authorization, accounting, centralized policy management, and integration with other network services, should help you prepare for questions related to AAA on the CompTIA 1101 exam.

54
Q

Services provided by networked hosts: Spam gateways

A

Email is essential to business. In the past, email spam has comprised up to half of the email traffic on the Web.

Spam gateways are email filters that can detect almost all spam coming into a system,
which increases email efficiency and network security as well.

These gateways can be on-premises and attached to the email server or can be cloud-based, depending on how email is
structured in an institution.

Spam Filtering Techniques: You should understand various techniques used by spam gateways to filter and block spam emails, such as content-based filtering, blacklisting, whitelisting, Bayesian filtering, SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), DMARC (Domain-based Message Authentication, Reporting, and Conformance), and other anti-spam techniques.

Anti-Virus and Anti-Malware: Spam gateways may include anti-virus and anti-malware features to detect and block email attachments or links that contain malicious software, viruses, or malware. You should understand how these features work and their importance in protecting against email-borne threats.

Quarantine and Message Management: Spam gateways may provide quarantine and message management features that allow administrators or end-users to manage spam emails, false positives, and false negatives. You should understand how to manage quarantined emails, review message logs, release legitimate emails, and handle false positives or false negatives.

Email Authentication and Reputation Management: Spam gateways may use email authentication techniques, such as SPF, DKIM, and DMARC, to verify the legitimacy of incoming emails and assess the reputation of sending domains or IP addresses. You should understand how these techniques work and their role in preventing email spoofing and phishing attacks.

Reporting and Logging: Spam gateways may generate reports and logs that provide insights into spam activity, email delivery, and other metrics. You should understand how to interpret these reports and logs, and use them for monitoring, troubleshooting, and security analysis.

Integration with Email Infrastructure: Spam gateways may integrate with email infrastructure, such as mail servers, email clients, and directory services, to provide seamless email filtering and management. You should understand how to configure and integrate spam gateways with existing email infrastructure for optimal performance and security.

Regular Updates and Maintenance: Spam gateways may require regular updates, patches, and maintenance to ensure optimal performance and protection against new spamming techniques.

You should understand the importance of keeping spam gateways up-to-date and following best practices for maintenance and security.

Understanding these key concepts related to spam gateways as an internet appliance should help you prepare for questions on this topic on the CompTIA 1101 exam.

55
Q

Services provided by networked hosts: UTM

A

Unified threat management (UTM) devices provide firewall, remote access, virtual private
network (VPN) support, web traffic filtering with anti-malware, and network intrusion prevention.

UTM devices can be specialized boxes that are placed between the organization’s network and the
Internet, but they can also be virtual machines that use cloud-based services.

UTM devices unitethe functions of several earlier devices and have largely replaced IDS and IPS devices (described next).

Barracuda Networks, Check Point, Cisco, and other networking equipment manufacturers
offer versions of UTM devices.

UTM Overview: Understand the concept of UTM, which refers to a comprehensive security solution that combines multiple security features, such as firewall, intrusion detection and prevention (IDP), virtual private network (VPN), antivirus, antispam, content filtering, and other security measures into a single device or solution.

Security Features: Familiarize yourself with the different security features typically included in a UTM solution, such as firewall, IDP, VPN, antivirus, antispam, content filtering, web filtering, application control, and other security measures. Understand how these features work together to provide comprehensive security against various threats, including malware, viruses, spam, intrusions, and other security risks.

Configuration and Management: Learn how to configure and manage UTM devices or solutions, including setting up firewall rules, managing IDP policies, configuring VPN connections, configuring antivirus and antispam settings, creating content filtering rules, managing web filtering and application control policies, and other administrative tasks related to UTM.

Threat Intelligence: Understand the importance of threat intelligence in UTM, which involves using up-to-date threat information, such as threat signatures, blacklists, whitelists, and reputation databases, to identify and block known threats. Learn how UTM devices or solutions leverage threat intelligence to provide proactive security against known threats.

Logging and Reporting: Familiarize yourself with the logging and reporting capabilities of UTM devices or solutions, which involve capturing and analyzing logs, generating reports, and providing insights into security events, threats, and other activities. Understand how to interpret logs and reports to identify security incidents, troubleshoot issues, and assess the effectiveness of UTM security measures.

UTM Deployment Scenarios: Gain an understanding of different deployment scenarios for UTM, including on-premises deployments, cloud-based deployments, and hybrid deployments. Understand the advantages and considerations of each deployment scenario, and how UTM can be integrated into a network architecture to provide effective security.

Best Practices: Learn best practices for UTM implementation and management, including keeping UTM devices or solutions up-to-date with the latest security patches and updates, configuring strong authentication and access controls, regularly reviewing and updating security policies, monitoring logs and reports for security events, and following other industry best practices for UTM security.

56
Q

Load balancers

A

Load balancing refers to sharing tasks and traffic in a network for maximum efficiency.

When balancing traffic within a network or handling application processing between servers, the work is shared among all the available resources on a network instead of occurring on only one device.

For example, network load balancing occurs when inbound or outbound traffic can be split up and routed to the destination in different ways to enhance speed, with the data reassembled at the
destination for processing.

A load balancer increases redundancy and performance by distributing the load to multiple servers.

Network load balancers are often reverse proxy servers configured in a cluster to provide scalability and high availability.

Load Balancing Overview: Understand the concept of load balancing, which involves distributing network traffic across multiple servers or resources to optimize resource utilization, enhance performance, and ensure high availability and reliability of applications or services.

Load Balancing Algorithms: Familiarize yourself with different load balancing algorithms, such as round-robin, least connections, source IP affinity, and others. Understand how these algorithms work and their pros and cons in different scenarios.

Load Balancer Types: Learn about different types of load balancers, including hardware load balancers, software-based load balancers, and cloud-based load balancers. Understand their features, advantages, and considerations for different deployment scenarios.

Configuration and Management: Gain knowledge of how to configure and manage load balancers, including setting up server pools, configuring load balancing algorithms, managing health checks, setting up virtual IPs, and other administrative tasks related to load balancing.

High Availability and Scalability: Understand how load balancers can provide high availability and scalability for applications or services by distributing traffic across multiple servers, detecting server failures, and automatically redirecting traffic to healthy servers.

SSL Offloading: Learn about SSL offloading or SSL termination, which involves offloading the SSL/TLS encryption and decryption process from the servers to the load balancer. Understand the benefits and considerations of SSL offloading in load balancing scenarios.

Monitoring and Troubleshooting: Familiarize yourself with monitoring and troubleshooting techniques for load balancers, including monitoring server health, analyzing traffic patterns, troubleshooting load balancing issues, and identifying performance bottlenecks.

Security Considerations: Gain an understanding of security considerations in load balancing, such as protecting against denial of service (DoS) attacks, securing communication between load balancers and servers, and implementing access controls for load balancer management interfaces.

57
Q

Proxy servers

A

A proxy server is an intermediary between a client and another network, such as the Internet.

A proxy server stores web pages that have been requested; if a client requests a web page, the proxy server checks its cache for the page.

If the page exists and is up-to-date, the proxy server uses its cached copy to supply the client’s request. If the proxy server does not have the requested page, it downloads the page on behalf of the client, sends the page to the client, and retains a copy of the page in its cache.

A proxy server reduces traffic between a network and the Internet, and it can also block requests for undesirable traffic. In addition, proxy servers can be used for anonymous surfing.

See https://whatis.techtarget.com/definition/proxy-server for more information on how proxy servers
are used.

Proxy Server Overview: Understand the concept of a proxy server, which acts as an intermediary between clients and servers, allowing clients to access resources indirectly through the proxy server.

Proxy Server Types: Familiarize yourself with different types of proxy servers, including forward proxies, reverse proxies, transparent proxies, and caching proxies. Understand their functions, use cases, and advantages.

Proxy Server Features: Learn about common features of proxy servers, such as caching, filtering, authentication, and logging. Understand how these features can enhance security, performance, and control in a network environment.

Proxy Server Protocols: Gain knowledge of various protocols used by proxy servers, including HTTP, HTTPS, FTP, SOCKS, and others. Understand how these protocols are used in different proxy server types and scenarios.

Configuration and Management: Understand how to configure and manage proxy servers, including setting up proxy rules, managing access controls, configuring caching and filtering settings, and monitoring proxy server activity.

Security Considerations: Gain an understanding of security considerations in proxy server deployments, such as protecting against unauthorized access, securing communication between clients and proxy servers, and logging and monitoring for security purposes.

Proxy Server Benefits and Limitations: Understand the benefits and limitations of using proxy servers, including improved security, increased privacy, enhanced performance, but also potential limitations in terms of configuration complexity, potential single point of failure, and impact on user experience.

Troubleshooting: Familiarize yourself with common issues and troubleshooting techniques related to proxy servers, such as diagnosing connectivity issues, resolving caching problems, and identifying and resolving configuration errors.

58
Q

Legacy/embedded systems: SCADA

A

The term legacy refers to something handed down from predecessors. Legacy systems, therefore, are systems that use outdated operating systems, programming languages, applications, or hardware.

Maintaining legacy systems is often necessary when newer products are not compatible with legacy applications (for example, applications that can run only under MS-DOS or old
versions of Windows).

If a legacy operating system and its applications can be run in a virtualized environment, the
problems of maintaining old hardware are eliminated.
Embedded systems are dedicated computing devices used for specific tasks, such as machine
control, point-of-sale systems, or ATMs.

Embedded systems commonly are found in Supervisory
Control and Data Acquisition (SCADA) systems.

SCADA systems are designed to provide centralized control for managing industrial equipment, such as in manufacturing or water and waste treatment plants.

SCADA systems connect equipment to a typically secure network that
facilitates communication between operators and machines.

Operators can collect and analyze
data from various components, as well as modify configurations or operations.

SCADA systems
can be complex because many different components are working together to ensure the
the functionality of the equipment or process.

Embedded systems often also are legacy systems; as
long as they work, they are maintained. Embedded systems are very specialized in nature and
often run older operating systems because of the way the systems are designed and whether they
allow the manufacturer to upgrade the operating system.

Perhaps the biggest risk to both legacy and embedded systems is security. If a legacy system or an
embedded system has network or Internet connectivity, it theoretically could be attacked or used as a bot to attack other systems.

This is a great concern for organizations that utilize SCADA
systems because many manage critical infrastructure equipment in facilities such as power plants,
dams, nuclear reactors, and water and waste treatment.

Although operating systems designed for embedded uses have more security than standard operating systems, older operating systems face the greatest risks.

SCADA Overview: Understand the concept of SCADA, which is a type of industrial control system used to monitor and control industrial processes, such as manufacturing, power generation, and water treatment. SCADA systems typically consist of remote terminal units (RTUs), supervisory computers, and human-machine interfaces (HMIs).

SCADA Components: Familiarize yourself with the different components of a SCADA system, including sensors, actuators, RTUs, PLCs (Programmable Logic Controllers), communication networks, and HMIs. Understand their functions and how they work together to enable monitoring and control of industrial processes.

SCADA Architecture: Gain knowledge of the common SCADA system architectures, including centralized, distributed, and hybrid architectures. Understand their advantages, disadvantages, and use cases in different industrial environments.

SCADA Protocols: Learn about common protocols used in SCADA systems, such as Modbus, DNP3, OPC (OLE for Process Control), and others. Understand how these protocols are used for communication between different components of a SCADA system.

SCADA Security: Understand the unique security challenges of SCADA systems, including protecting against unauthorized access, ensuring data integrity and confidentiality, and defending against cyber threats. Learn about security best practices, such as network segmentation, access controls, authentication, encryption, and monitoring, to protect SCADA systems from security risks.

SCADA Operations and Monitoring: Familiarize yourself with SCADA operations and monitoring, including configuring and managing RTUs and PLCs, setting up alarms and notifications, monitoring system performance, and troubleshooting issues.

SCADA Applications: Gain an understanding of different applications of SCADA systems in industrial environments, such as process monitoring and control, equipment diagnostics and maintenance, data logging and reporting, and remote operation and management of industrial processes.

SCADA Regulations and Standards: Learn about relevant regulations and standards related to SCADA systems, such as NERC CIP (North American Electric Reliability Corporation Critical Infrastructure Protection), ISA/IEC 62443 (Industrial Automation and Control Systems Security), and others. Understand the requirements and best practices outlined in these standards for securing SCADA systems.

59
Q

IoT devices

A

Thermostats

Light switches

Security cameras

Door locks

Voice-enabled smart

speakers/digital assistants

The Internet has long connected people together, but in recent years, the explosive growth of the
the web has involved connections between people and the objects that they use.

As communication
protocols such as Bluetooth and Z-Wave have evolved, and production techniques have made it easier
to embed communication capability into smaller and less expensive objects that are common in
people’s everyday life.

Markets for Internet of Things (IoT) devices are expanding—consider
phones, cars, home appliances, door locks, wall outlets, lights, and video-enabled doorbells,
among many other devices. Industrial uses are being developed as well, and now devices can
measure soil moisture, noise, motion, air pressure, and water pressure.

Many billions of objects
are now talking to each other and sharing data, and the number of such devices is expected to
grow exponentially.

IoT Overview: Understand the concept of IoT, which refers to the network of interconnected devices (such as sensors, actuators, and other smart devices) that can communicate, exchange data, and perform tasks without human intervention. Learn about the various applications of IoT in different industries, such as healthcare, transportation, smart homes, and industrial automation.

IoT Device Types: Familiarize yourself with different types of IoT devices, including sensors, actuators, wearables, smart appliances, industrial devices, and others. Understand their functions, capabilities, and use cases.

IoT Communication Protocols: Learn about common communication protocols used in IoT devices, such as MQTT, CoAP, Bluetooth, Zigbee, and others. Understand how these protocols enable communication between IoT devices and with other parts of the IoT ecosystem, such as gateways, cloud platforms, and applications.

IoT Security: Understand the unique security challenges of IoT devices, including protecting against unauthorized access, ensuring data privacy and integrity, and defending against IoT-specific threats, such as device spoofing, data tampering, and IoT botnets. Learn about security best practices, such as device authentication, encryption, over-the-air (OTA) updates, and security monitoring, to mitigate risks associated with IoT devices.

IoT Data Management: Gain knowledge of IoT data management concepts, including data collection, storage, processing, and analysis. Understand the importance of data governance, data privacy, and data analytics in IoT deployments.

IoT Deployment Considerations: Learn about important considerations for deploying IoT devices, such as network connectivity, power management, scalability, interoperability, and device lifecycle management. Understand the challenges and best practices for deploying and managing large-scale IoT deployments.

IoT Standards and Frameworks: Familiarize yourself with relevant standards and frameworks related to IoT, such as MQTT, CoAP, IEEE 802.15.4, Open Connectivity Foundation (OCF), and others. Understand their role in ensuring interoperability and security in IoT ecosystems.

IoT Applications and Use Cases: Gain an understanding of different applications and use cases of IoT devices in various industries, such as smart homes, smart cities, healthcare, transportation, agriculture, and industrial automation. Understand how IoT devices are used to enable new services, improve efficiency, and enhance user experiences.

60
Q

Install and configure basic wired/wireless small office/home office (SOHO) networks: IPv4 Private and Public addresses

A

Public IP addresses can be discovered and seen by anyone on the Web. Private IP addresses are
not routable to the Web and can be used only inside a local area network (LAN). For most SOHO
networks, an ISP provides a single public IP address to a customer.

The address provided gives
access to the Web and is discoverable by anyone on the Internet.

That IP address is usually
assigned to the interface of the SOHO router that connects to the ISP.

Inside a SOHO network, private IP addresses are used to identify each device on the network.

Private addresses are used for a couple reasons. First, the limited number of available public IPv4
addresses is not nearly sufficient to meet demand.

IPv4 was not designed with the explosive growth of connected devices in mind, and private addressing was a solution to the address shortage.

Second, using private addresses inside a network adds security because devices cannot
be discovered from the Internet.
A few easy clues can help determine whether an IP address is public or private, and those come in the first numbers of the IP address.

Private addresses fall in one of three addressing ranges:
10.0.0.0–10.255.255.255
172.16.0.0–172.31.255.255
192.168.0.0–192.168.255.255

IPv4 Addressing: Understand the basics of IPv4 addressing, including the format of IPv4 addresses (e.g., four sets of decimal numbers separated by periods), the concept of octets (8-bit groups), and the purpose of subnet masks.

Private IPv4 Addresses: Familiarize yourself with the reserved private IPv4 address ranges, which are reserved for use within private networks and are not routable over the public internet. The most commonly used private IPv4 address ranges are:

10.0.0.0 to 10.255.255.255 (10.0.0.0/8)
172.16.0.0 to 172.31.255.255 (172.16.0.0/12)
192.168.0.0 to 192.168.255.255 (192.168.0.0/16)

Understand how these private IPv4 addresses can be used to configure IP addressing within a small office/home office (SOHO) network and allow devices on the network to communicate with each other.

Public IPv4 Addresses: Understand that public IPv4 addresses are routable over the public internet and are assigned by the Internet Assigned Numbers Authority (IANA) to Internet Service Providers (ISPs) or organizations for use on the public internet.

Public IPv4 addresses are unique and globally routable, allowing devices on different networks to communicate with each other over the internet.

Network Address Translation (NAT): Understand the concept of Network Address Translation (NAT), which is used to translate private IPv4 addresses to public IPv4 addresses when devices on a private network need to communicate with devices on the public internet.

Understand the purpose of NAT and how it enables devices with private IPv4 addresses to communicate with the public internet using a single public IPv4 address.

IPv4 Address Assignment: Understand the methods for assigning IPv4 addresses to devices in a SOHO network, including static IP addressing and dynamic IP addressing using DHCP (Dynamic Host Configuration Protocol). Understand the benefits and limitations of each method and how to configure and manage IP addressing on wired/wireless devices in a SOHO network.

Subnetting: Gain a basic understanding of subnetting, which involves dividing a larger IP address space into smaller, manageable subnets.

Understand the concept of subnet masks and how they are used to identify the network portion and host portion of an IPv4 address. Familiarize yourself with common subnet masks and how to use them to configure IP addressing within a SOHO network.

61
Q

IPv6

A

IPv6 Addressing: Understand the basics of IPv6 addressing, including the format of IPv6 addresses (e.g., eight sets of hexadecimal numbers separated by colons), the longer address space compared to IPv4, and the use of colons and double colons to represent consecutive blocks of zeroes.

IPv6 Features: Familiarize yourself with the features of IPv6, such as increased address space, improved security, enhanced mobility, and simplified network management. Understand the advantages of IPv6 over IPv4 and the reasons for its adoption.

IPv6 Address Types: Understand the different types of IPv6 addresses, including global unicast addresses (similar to public IPv4 addresses), link-local addresses (used for communication within a local network segment), and multicast addresses (used for one-to-many communication). Familiarize yourself with the purpose and usage of each type of IPv6 address.

IPv6 Address Assignment: Understand the methods for assigning IPv6 addresses to devices, including manual configuration, stateless autoconfiguration (SLAAC), and stateful address configuration using DHCPv6 (Dynamic Host Configuration Protocol for IPv6). Understand the benefits and limitations of each method and how to configure and manage IPv6 addressing on wired/wireless devices.

IPv6 Transition Mechanisms: Gain a basic understanding of IPv6 transition mechanisms, which are used to enable communication between IPv6 and IPv4 networks during the transition period. Familiarize yourself with common transition mechanisms such as dual-stack, tunneling, and translation, and understand their purpose and usage.

IPv6 Routing: Understand the basics of IPv6 routing, including the use of routing tables, routing protocols (such as OSPFv3 and RIPng), and the concept of neighbour discovery for finding neighbouring devices on a local network segment.

IP version 6 (IPv6) greatly increases the number of available IP addresses for computers,
smartphones, and other mobile devices.

IPv6 uses 128-bit source and destination IP addresses
(compared to 32-bit for IPv4), theoretically enabling up to 340 undecillion addresses (3.4×1038).
(This number is largely unimaginable to humans; 340 undecillion is said to exceed the number of
grains of sand on Earth.)

IPv6 also features built-in security and provides better support for
quality of service (QoS) routing, which is important to achieve high-quality streaming audio and
video traffic. Windows, macOS, and Linux all support IPv6.

IPv6 Addressing
IPv6 addresses start out as 128-bit addresses that are each then divided into eight 16-bit blocks.
The blocks are converted into hexadecimal, and each block is separated from the following block
by a colon. Leading zeros are typically suppressed, but each block must contain at least one digit.

Consider a typical IPv6 address:
21DA:D3:0:2F3B:2AA:FF:FE28:9C5A
A contiguous sequence of 16-bit blocks set to zero can be represented by the double colon (::).

This technique is also known as zero compression. To determine the number of zero bits
represented by the double colon, count the number of blocks in the compressed address, subtract
the result from 8, and multiply the result by 16.

An address can include only one zero-compressed
block.

This IPv6 address uses the double colon:

FF02::2.

Two blocks exist here: FF02 and 2. So how many zero bits does the double colon represent?
Subtract 2 from 8 (8 − 2 = 6) and then multiply 6 by 16 (6 × 16 = 96). This address includes a
block of 96 zero bits.

The loopback address on an IPv6 system is 0:0:0:0:0:0:0:1, which is abbreviated as ::1.

Thus, if
you want to test your network interface in Windows where IPv6 is enabled by default, you can
type ping ::1 at a command prompt.

IPv6 Address Types
IPv6 supports three types of addresses: unicast, multicast, and anycast.

Five types of unicast
addresses exist:Global unicast addresses: Global unicast addresses are used in the same way as IPv4 public
addresses.

The first 3 bits are set to 001 and the following 45 bits are used for the global
routing prefix; these 48 bits are collectively known as the public topology. The subnet ID
uses the next 16 bits and the interface ID uses the remaining 64 bits.

Link local addresses: Link local addresses correspond to the Automatic Private IP
Addressing (APIPA) address scheme used by IPv4 (addresses that start with 169.254). The
first 10 bits are set to FE80 hex, followed by 54 zero bits and 64 bits for the interface ID.

Using zero compression, the prefix is thus FE80::/64. As with APIPA, link local addresses
are not forwarded beyond the link.
Site local addresses: Site local addresses use the prefix FEC0:: and correspond to IPv4
private address spaces (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16).
Special addresses: Special addresses include unspecified addresses (0:0:0:0:0:0:0:0 or ::),
which are equivalent to IPv4’s 0.0.0.0 and indicate the absence of an IP address; a loopback
address (0:0:0:0:0:0:0:1 or ::1) is equivalent to the IPv4 loopback address 127.0.0.1.

Compatibility addresses: Compatibility addresses are used when both IPv4 and IPv6 are in
use. In the following examples, w.x.y.z is replaced by the actual IPv4 address.

An IPv4-
compatible address (0:0:0:0:0:0:w.x.y.z or ::w.x.y.z) is used by nodes that support IPv4 and
IPv6 communicating over IPv6. An IPv4-mapped address (0:0:0:0:0:FFFF:w.x.y.z or
::FFFF:w.x.y.z) represents an IPv4-only node to an IPv6 node.

A 6to4 address is used when
two nodes running both IPv4 and IPv6 connect over an IPv4 link. The address combines the
prefix 2002::/16 with the IPv4 public address of the node. ISATAP can also be used for the
connection; it uses the locally administered ID::0:5EFE:w.x.y.z (where w.x.y.z is any unicast
IPv4 address, either public or private). Teredo addresses are used for tunneling IPv6 over
UDP through network address translation (NAT); they use the prefix 3FFE:831F::/32.

Both IPv4 and IPv6 support multicasting, which enables one-to-many distribution of content such
as Internet TV or other types of streaming media.

IPv6 multicast addresses begin with FF.

Anycast addressing sends information to a group of potential receivers that are identified by the
same destination address. This is also known as a one-to-one-to-many association.

Anycast
addressing can be used for distributed services, such as DNS or other situations in which
automatic failover is desirable. IPv6 uses anycast addresses as destination addresses that are
assigned only to routers. Anycast addresses are assigned from the unicast address space.

62
Q

APIPA

A

Most IP networks use addresses provided automatically by the Dynamic Host Configuration
Protocol (DHCP). However, if the DHCP server becomes unavailable and an alternate IP address
has not been set up, devices on the network assign themselves Automatic Private IP Addressing
(APIPA) or link-local addresses.

These addresses are in the IPv4 address range 169.254.0.1 to
169.254.255.254 (with the subnet mask 255.255.0.0); the IPv6 version is called a link local
address and has the FE80::/64 prefix. A device with an APIPA address cannot connect to the
Internet.

Purpose: Understand that APIPA is designed to provide a temporary, self-assigned IP address to a device when it cannot obtain an IP address from a DHCP server. This allows the device to maintain basic network connectivity in the absence of a DHCP server.

IP Address Range: Know that APIPA uses the IP address range of 169.254.0.1 to 169.254.255.254, with a subnet mask of 255.255.0.0. Devices that are configured to use APIPA will automatically assign themselves an IP address from this reserved range if they fail to obtain an IP address from a DHCP server.

Limitations: Understand that APIPA is intended for use in small, local networks and is not suitable for larger networks or the Internet. Devices configured with APIPA can only communicate with other devices on the same local network segment that are also using APIPA, and cannot communicate with devices outside of this segment.

Troubleshooting: Be familiar with common issues related to APIPA, such as devices not obtaining an IP address from a DHCP server, conflicts with other devices using APIPA, and potential network connectivity issues due to limitations of APIPA. Understand how to troubleshoot and resolve these issues.

Disabling APIPA: Understand how to disable APIPA if it is not desired or required in a network environment. This may involve configuring a static IP address or resolving DHCP server issues to ensure proper IP address assignment.

Understanding these key points about APIPA, including its purpose, IP address range, limitations, troubleshooting, and disabling options, can help you prepare for questions related to APIPA on the CompTIA 1101 exam.

63
Q

Static

A

The term static means “unchanging” or “always the same.” Dynamic means “constantly
changing.” These terms describe the two most common ways to configure a computer’s IP address
settings.

Static IP address: Assigned to a device by the administrator and not subject to change until
reconfigured by the administrator. Note that more than just the IP address must be
configured; other areas are the subnet mask, the default gateway, and DNS servers.

Static IP addressing refers to manually assigning a fixed IP address to a device on a network, instead of using dynamic IP addressing where IP addresses are automatically assigned by a DHCP server. Here’s a concise summary of what you need to know about static IP addressing for the CompTIA 1101 exam:

Purpose: Understand that static IP addressing is used to assign a specific IP address to a device on a network, and this IP address remains unchanged unless manually reconfigured. Static IP addresses are typically used for devices that require consistent, predictable IP addresses, such as servers, routers, and network printers.

Configuration: Know how to manually configure a device with a static IP address, including specifying the IP address, subnet mask, default gateway, and DNS server settings. Understand the importance of assigning a unique IP address within the appropriate IP address range and subnet for the network.

Benefits and Drawbacks: Understand the advantages of using static IP addresses, such as maintaining consistent IP address assignments for critical devices, avoiding IP address conflicts, and simplifying network troubleshooting. Also, understand the drawbacks of using static IP addresses, including the need for manual configuration and potential issues with scalability and manageability in large networks.

Troubleshooting: Be familiar with common issues related to static IP addressing, such as incorrect IP address configurations, subnet mask mismatches, and default gateway or DNS server misconfigurations. Understand how to troubleshoot and resolve these issues.

Best Practices: Know best practices for using static IP addressing, such as documenting all static IP address assignments, using reserved IP address ranges, and regularly reviewing and updating static IP address assignments to ensure accuracy and consistency.

64
Q

Dynamic

A

Dynamic (DHCP server-assigned) IP address: Assigned by a DHCP server and likely to
change each time a device leaves and then rejoins the network, or when the address is used
beyond its lease time and expires.

Dynamic IP addressing refers to the automatic assignment of IP addresses to devices on a network by a DHCP (Dynamic Host Configuration Protocol) server. Here’s a concise summary of what you need to know about dynamic IP addressing for the CompTIA 1101 exam:

Purpose: Understand that dynamic IP addressing is used to automatically assign IP addresses to devices on a network, eliminating the need for manual configuration. Dynamic IP addresses are typically used for devices that do not require consistent or predictable IP addresses, such as client devices like computers, smartphones, and tablets.

Configuration: Know how to configure devices to obtain IP addresses dynamically through DHCP, including enabling DHCP client functionality on network devices and configuring DHCP options such as lease duration, DNS server settings, and gateway information.

Benefits and Drawbacks: Understand the advantages of using dynamic IP addresses, such as ease of management, scalability, and flexibility in large networks. Also, understand the drawbacks of using dynamic IP addresses, including the potential for IP address conflicts, the reliance on a DHCP server for IP address assignments, and the need for proper DHCP server configuration and management.

Troubleshooting: Be familiar with common issues related to dynamic IP addressing, such as DHCP server misconfigurations, DHCP client failures, and IP address conflicts. Understand how to troubleshoot and resolve these issues.

Best Practices: Know best practices for using dynamic IP addressing, such as regularly monitoring and managing DHCP leases, configuring DHCP options correctly, and implementing proper network segmentation to minimize potential issues with IP address conflicts.

65
Q

Gateway

A

Identifies the IP address of the
device that connects the computer to the Internet or another network; same values for all devices on the
network.

In the context of networking and the CompTIA 1101 exam, a gateway refers to a network device or software that acts as an interface between different networks, enabling communication between them. Here’s a concise summary of what you need to know about gateways for the exam:

Purpose: Understand that a gateway serves as a point of entry or exit for data packets between different networks, such as connecting a local area network (LAN) to a wide area network (WAN) or connecting different types of networks, such as Ethernet and Wi-Fi.

Functionality: Know the basic functions of a gateway, including packet forwarding, routing, and network address translation (NAT), which allows devices on one network to communicate with devices on another network using different IP address schemes.

Types of Gateways: Be familiar with different types of gateways, such as default gateways, which are used to forward data packets from devices on a local network to devices on other networks; application gateways, which provide security features by inspecting and filtering application-layer traffic; and protocol-specific gateways, which are designed to work with specific protocols, such as DNS (Domain Name System) gateways or DHCP (Dynamic Host Configuration Protocol) relay gateways.

Configuration: Understand how to configure gateways, including setting up routing tables, configuring NAT settings, and managing gateway security features, such as firewalls and access control lists (ACLs).

Troubleshooting: Be familiar with common issues related to gateways, such as routing errors, NAT configuration issues, and firewall misconfigurations. Understand how to troubleshoot and resolve these issues.

Best Practices: Know best practices for gateway configuration and management, such as keeping firmware and software up-to-date, securing gateway access with strong authentication methods, and implementing proper network segmentation to isolate different types of traffic and improve network security.

66
Q

What is a DNS ‘A’ Address?

A

example.com. IN A 192.168.1.1

DNS A records contain the IP address of a domain, specifically the IPv4 address.

In summary, the “A” in “A record” is not referring to DNS itself, but rather to a specific type of DNS resource record used to map domain names to IPv4 addresses.

Essentially, an A record tells the DNS resolver what IPv4 address is associated with a specific domain name, so that when someone types in a domain name (e.g., www.example.com) in their web browser, the DNS resolver can look up the A record for that domain name and retrieve the corresponding IPv4 address (e.g., 192.168.1.1).

An A DNS (Domain Name System) address, also known as an “A record,” is a type of DNS resource record that maps a domain name to an IPv4 address. In other words, it’s a way to associate a human-readable domain name, such as www.example.com, with a numerical IPv4 address, such as 192.168.1.1.

This allows computers to locate and connect to web servers and other resources on the internet using domain names instead of remembering numerical IP addresses. A DNS resolver, which is responsible for translating domain names to IP addresses, uses A DNS records to retrieve the corresponding IPv4 address associated with a specific domain name.

The A record is the most important DNS record type. The “A” in A record stands for “address.” An A record shows the IP address for a specific hostname or domain.

67
Q

DNS ‘AAAA’ is what?

A

example.com. IN AAAA 2001:0db8:85a3:0000:0000:8a2e:0370:7334

An AAAA DNS (Domain Name System) address, also known as an “AAAA record,” is a type of DNS resource record that maps a domain name to an IPv6 address.

An A record is used to map a domain name to an IPv4 address, while an AAAA record is used to map a domain name to an IPv6 address.

AAAA records allow websites and other resources to be accessed over IPv6 networks, which offer increased address space and improved security compared to IPv4. Just like A records, DNS resolvers use AAAA records to retrieve the corresponding IPv6 address associated with a specific domain name.

68
Q

Mail Exchanger (MX)

A

A mail exchanger record (MX record) specifies the mail server responsible for accepting email messages on behalf of a domain name. It is a resource record in the Domain Name System (DNS).

In the context of DNS, the term “MX” stands for “Mail Exchanger.” An MX record is a type of DNS resource record that is used to specify the mail server(s) responsible for accepting incoming email messages for a domain.

When someone sends an email to an address at a particular domain (e.g., user@example.com), the sender’s email server needs to know which mail server is responsible for accepting emails for that domain. The MX record in the DNS zone for the domain specifies the hostname or domain name of the mail server(s) that should receive email messages for that domain.

MX records are used in email delivery to route incoming email messages to the correct mail server. When an email is sent to a particular domain, the sender’s email server looks up the MX record for that domain in the DNS to determine the hostname or domain name of the mail server(s) that should receive the email. The sender’s email server then routes the email to the mail server(s) specified in the MX record.

For example, a typical MX record entry in a DNS zone file might look like this:

example.com. IN MX 10 mail.example.com.

In this example, “example.com” is the domain name, “IN” specifies the DNS class (typically “IN” for Internet), “MX” indicates the type of record (MX record for mail exchanger), “10” is the priority of the mail server (lower values indicate higher priority), and “mail.example.com” is the hostname or domain name of the mail server responsible for accepting incoming email messages for the domain “example.com”.

Understanding MX records and how they work is important for configuring email services and ensuring proper email delivery for a domain.

69
Q

Text (TXT) in DNS records

A

(TXT) records provide text information for sources outside of your domain. You add these records to your domain settings. You can use TXT records for various purposes. For example, some use them to verify domain ownership and to ensure email security. Let’s investigate these record types more closely.

In the context of DNS, a TXT record is a type of DNS resource record that is used to store arbitrary text data associated with a domain name. TXT records are commonly used for various purposes, such as adding human-readable notes, providing information for domain ownership verification, and storing SPF (Sender Policy Framework) data for email authentication.

A TXT record typically consists of a domain name, a DNS class (such as “IN” for Internet), “TXT” indicating the type of record, and the text data enclosed in double quotation marks. The text data can be any free-form text, and it can include letters, numbers, symbols, and whitespace. TXT records can be used to store multiple lines of text data, which are typically concatenated into a single string with line breaks.

For example, a typical TXT record entry in a DNS zone file might look like this:

example.com. IN TXT “v=spf1 include:spf.example.com -all”

In this example, “example.com” is the domain name, “IN” specifies the DNS class, “TXT” indicates the type of record (TXT record for text data), and “v=spf1 include:spf.example.com -all” is the text data associated with the domain.

In this case, the text data is an SPF record, which is used for email authentication and specifies the allowed mail servers for sending email on behalf of the domain.

TXT records are versatile and can be used for various purposes beyond SPF, such as storing DKIM (DomainKeys Identified Mail) keys for email authentication, providing domain ownership verification for services like Google Workspace or Microsoft Office 365, and adding human-readable notes or comments for documentation or troubleshooting purposes.

Understanding TXT records and how they are used can be important for managing DNS configurations and ensuring proper domain functionality.

70
Q

Text (TXT) Spam Management

A

DKIM: DomainKeys identified mail

SPF: sender policy framework

DMARC: domain-based message authentication, reporting and conformance

Other DNS tools that can protect email from spam follow:

DomainKeys Identified Mail (DKIM): A process that enables a receiving mail system to
make sure that the sending party authorized the message and was not used for spam
or phishing.

Sender Policy Framework (SPF): A tool that lets domain owners list the IP addresses that
are authorized to send mail, to control spam.

Domain-based Message Authentication, Reporting, and Conformance (DMARC): A mail
authentication process that builds on DKIM and SPF to further enhance security from
fraudulent spam.

In the context of DNS, spam management using a TXT record typically involves using the Sender Policy Framework (SPF) or DomainKeys Identified Mail (DKIM) mechanisms to authenticate and authorize legitimate sources of email for a domain, and thereby help prevent email spoofing and spamming.

SPF is a method used by domain owners to specify which mail servers are authorized to send email on behalf of their domain. SPF records are created as TXT records in the DNS and contain information about the mail servers that are allowed to send email for a particular domain. When an incoming email is received, the receiving mail server can check the SPF record for the domain in the DNS to verify if the sender’s mail server is authorized to send email on behalf of that domain. If the sender’s mail server is not listed in the SPF record, the receiving mail server may consider the email as potentially suspicious and may apply spam filtering or reject the email altogether.

DKIM, on the other hand, is a method used to digitally sign outgoing email messages from a domain. A DKIM signature is generated by the sending mail server and is added as a header to the email message. The DKIM signature can then be verified by the receiving mail server by looking up the public key in the domain’s DKIM TXT record in the DNS. If the DKIM signature is valid, it confirms the authenticity of the email and helps to ensure that it was not tampered with during transit.

Both SPF and DKIM are commonly used techniques for spam management in email systems. By implementing SPF and DKIM, domain owners can help prevent email spoofing and unauthorized use of their domain in spamming or phishing attacks, and improve the overall security and reliability of their email communication.

Configuring SPF and DKIM records as TXT records in the DNS is part of the overall email security strategy for a domain, and understanding how to set up and manage SPF and DKIM records can be important for effective spam management in email systems. It may be relevant to the “2.6” section of the networking topic for the CompTIA A+ 1101 exam, which covers networking fundamentals and basic network configuration.

DMARC allows domain owners to specify how they want incoming email messages that claim to be from their domain to be handled. It provides a way for domain owners to set policies for how email messages that fail SPF and/or DKIM checks should be treated, such as being rejected, quarantined, or accepted with modifications. DMARC also provides reporting mechanisms that allow domain owners to receive feedback on email messages that pass and fail DMARC checks, which can help them identify and mitigate any potential abuse or unauthorized use of their domain.

DMARC policies are published as TXT records in the DNS, similar to SPF and DKIM records. The DMARC TXT record typically contains information about the domain’s DMARC policy, such as the desired handling of failed SPF and/or DKIM checks, and an email address where DMARC reports should be sent. When an incoming email claiming to be from a domain with a DMARC policy is received, the receiving mail server can check the DMARC policy in the DNS to determine how the email should be handled based on the policy set by the domain owner.

DMARC is designed to work in conjunction with SPF and DKIM, and it provides an additional layer of email authentication and authorization. By implementing DMARC, domain owners can further enhance their email security posture by providing a more comprehensive and standardized approach to email authentication and policy enforcement.

71
Q

DHCP: leases, reservations and scope

A

IP Address Leases: When a device (such as a computer, smartphone, or other network-enabled device) connects to a network that uses DHCP, it can request an IP address from a DHCP server. The DHCP server can dynamically assign an IP address to the requesting device for a specific lease period, which is a predefined amount of time. This assigned IP address is known as an IP address lease. The lease period typically ranges from a few minutes to several days, and the device must renew the lease before it expires to continue using the same IP address.

DHCP Reservations: DHCP reservations allow a network administrator to configure a DHCP server to always assign a specific IP address to a particular device based on its MAC address. A MAC address is a unique hardware address assigned to each network interface card (NIC) in a device. By creating a DHCP reservation, a network administrator can ensure that a specific device always receives the same IP address from the DHCP server, even if the device’s IP lease expires and is renewed. This can be useful, for example, when setting up servers or other devices that require a consistent IP address for remote access or other purposes.

DHCP Scope: A DHCP scope is a range of IP addresses that a DHCP server is configured to assign to devices on a particular network segment or subnet. It defines the pool of available IP addresses that the DHCP server can dynamically assign to devices that request an IP address. The DHCP scope also includes other configuration parameters, such as the subnet mask, default gateway, DNS server, and other options that are sent to the devices along with the IP address.

DHCP Relay: In some network configurations, DHCP clients and DHCP servers may be located on different subnets or VLANs. In such cases, a DHCP relay agent can be used to forward DHCP requests and responses between the clients and the server. The DHCP relay agent listens for DHCP requests from clients, then forwards them to the appropriate DHCP server, and relays the responses back to the clients. This allows devices on different subnets or VLANs to obtain IP addresses and other network configuration parameters from a centralized DHCP server.

Understanding the concepts of DHCP leases, reservations, scopes, and relay can be important for network configuration and troubleshooting in a DHCP-enabled network environment.

72
Q

VLAN

A

A virtual local area network (VLAN) is a group of computers on a local area network (LAN) that
are configured to behave as if they have their own separate LAN. Usually LANs are separated by
a router, but a switch might have the capability to group ports together to behave like a LAN
inside the switch.

Because the LAN exists in software configuration instead of in hardware, it is considered a VLAN. For example, if a LAN of 10 computers is divided evenly into VLAN 1 and VLAN 2, the computers in VLAN 2 will be able to communicate among themselves, but not withany hosts on VLAN 1.

The hosts in each VLAN will even have IP addresses on different networks, and communicating between VLANs will require the services of a router.

Virtual local area networks (VLANs) are logical subdivisions of a switch that segregate ports from one another as if they were in different LANs. VLANs offer another way to add a layer of separation between sensitive devices and the rest of the network.

For example, if only one device should be able to connect to the finance server, the device and the finance server could be placed in a VLAN separate from the other VLANs. As traffic between VLANs can occur only through a router, access control lists (ACLs) can be used to control the traffic allowed between VLANs.

These VLANs can also span multiple switches, meaning that devices connected to switches in different parts of a network can be placed in the same VLAN regardless of physical location.

VLANs have many advantages and only one disadvantage. The disadvantage is managerial overhead securing the VLANs. The advantages are:

Cost: Switched networks with VLANs are less costly than routed networks, since routers cost more than switches.

Performance: By creating smaller broadcast domains (each VLAN is a broadcast domain), performance improves.

Flexibility: Removes the requirement that devices in the same LAN (or in this case VLAN) be in the same location.

Security: Provides one more layer of separation at layers 2 and 3.

73
Q

VPN

A

Secure Remote Access: VPNs provide a secure way for remote users to access a private network over the Internet. By using encryption and authentication mechanisms, VPNs create a secure “tunnel” for data to travel between the remote user’s device and the private network, protecting the data from interception or tampering.

Privacy and Anonymity: VPNs can also provide privacy and anonymity by masking the user’s IP address and encrypting their Internet traffic. This can be useful for protecting sensitive data, maintaining privacy, or bypassing geographic restrictions, such as accessing geo-restricted content.

Types of VPN: There are several types of VPNs, including remote access VPNs and site-to-site VPNs. Remote access VPNs are used by individual users to connect to a private network from a remote location, typically using VPN client software installed on their devices. Site-to-site VPNs are used to connect entire networks or segments of networks over the Internet, allowing different locations of an organization to communicate securely with each other.

VPN Protocols: VPNs use different protocols to establish the secure connection and encrypt data. Common VPN protocols include Point-to-Point Tunneling Protocol (PPTP), Layer 2 Tunneling Protocol (L2TP), Internet Protocol Security (IPsec), and Secure Socket Layer/Transport Layer Security (SSL/TLS). Each protocol has its strengths and weaknesses in terms of security, performance, and compatibility.

VPN Considerations: When implementing a VPN, there are several considerations to take into account, such as authentication, encryption, network topology, and scalability. VPNs may require additional hardware, software, or configuration on both the client and server sides. VPNs also introduce additional overhead in terms of encryption and encapsulation, which can affect performance.

VPN Security: VPNs are used to provide secure communication, but it is important to ensure that proper security measures are in place. This includes using strong encryption, implementing proper authentication and authorization mechanisms, keeping VPN software and hardware up-to-date with security patches, and monitoring VPN traffic for potential security breaches.