Networking Fundamentals Flashcards
load balancer
internet appliance designed to spread requests over multiple servers to evenly distribute the demand and balance a system
Common load balancing configurations include identical, cross-region, and content-based load balancing.
(Cheryl is in charge of maintaining her company’s website accessibility. Upon inspection, she finds that too much traffic is being directed to one web server while other web servers are sitting idle. What internet appliance could Cheryl use to resolve this issue?)
Which sets of connectors are used for twisted pair cabling?
RJ 45 and RJ 11.
commonly for phone lines and ethernet, respectively.
What type of IP address is 192.168.15.211?
a private IPv4 address
IPv4 addresses follow the format of four decimal octets. IPv6 format is eight hexadecimal quartets. IP addresses that begin with 192.168 are in the RFC1918 set of private addresses.
William is publishing his company’s website to the internet and wants to ensure a secure connection. Which of these protocols should William use?
Hypertext Transfer Protocol Secure (HTTPS) is the secure version of the HTTP protocol. HTTPS is run on port 443.
What addressing scheme relieves the burden of being limited by IP addresses?
IVP6 addressing.
The public IPv4 address space has been exhausted for quite some time now, meaning that all of these addresses have been purchased or allocated, usually by an Internet Service Provider (ISP). Many technical savvy companies have already begun the transition to using IPv6, which contains a possible 340 undecillion addresses, or 2 to the 128th power (yes, a lot of addresses). Many, if not all, ISPs have IPv6 enabled equipment already in operation.
Static addresses
manually assigned and entered on a device. This will effectively disable DHCP. He should also reserve the IP address in the DHCP pool as good practice to prevent it from being leased to another device.
David is installing a new Web server at the office, but doesn’t want DHCP giving it a new IP address every time he has to reboot it during maintenance. What kind of address should David assign to the new Web server?
static address
LDAP (Lightweight Directory Access Protocol)
works in conjunction with Active Directory to provide user authentication and management in a network. It is the successor to the DAP (Directory Access Protocol).
In a Windows environment, this protocol is often associated with Active Directory for central management of a user database. What is this protocol called?
LDAP (lightweight directory access protocol)
router
device that connects multiple network devices and determines the best path for reaching a specified device using routing tables.
Routers are OSI Layer 3 devices and make decisions based on logical addresses.
Key functions of a router include connecting multiple network devices to one another, breaking up broadcast domains, and connecting one LAN to another LAN on a WAN.
switch
A device that works at OSI Layer 2, examines the header of incoming packets for the MAC address, and forwards the packet to the correct location. Switches can be managed or unmanaged
- A managed switch is one that allows for port configuration, traffic management, and traffic monitoring. Managed switches offer quality of service (QoS), redundancy, port mirroring, and VLANs.
- An unmanaged switch does not allow for configuration and passes on all data for a MAC address to its ports.
access points
technically any device to which a host can connect in order to access a network. Wired access points include hubs and switches. However, the term usually refers to a wireless access point (WAP) that allows Wi-Fi devices to connect to a network.
patch panel
dumb device that is essentially a large rack-mounted HUB whose sole purpose is to connect cables together. A dumb device is a device that broadcasts all data coming in through the input port out over all output ports. A dumb device, like a patch panel, makes no logical decisions and simply serves as a connection and relay point.
firewall
security appliance, either hardware or software, that filters network traffic based on a preconfigured set of rules
PoE - Power over Ethernet
technology that delivers power to devices over data lines, such as an ethernet cable, rather than having a separate power cord.
injector
midspan device that sits between the switch and the access point and supplies power via an ethernet connection
switch
sits in front of the midspan injector device and provides power to the ethernet cable.
PoE Power over Ethernet Standards - IEEE 802.3
PoE- 802.3af-15.4 W—WAPs, static surveillance cameras, VoIP phones
PoE+- 802.3at-30W—alarm systems, PTZ cameras, video IP phones
PoE++- 802.3bt (Type 3)-60 W—multi-radio WAPs, video conferencing equipment
PoE++- 802.3bt (Type 4)-100 W—laptops, flat-screen monitors
hub
Layer 1 device that sends all incoming data to all connected devices as a broadcast. Hubs are also known as multiport repeaters.
cable modem
connects to a cable line to provide connectivity. A cable modem is technically no longer a modem, however, since it does not modulate and demodulate analog signals.
DSL (digital subscriber line)
provides connectivity via a telephone line.
ONT (optical network terminal)
provides connectivity via a fiber-optic line.
NIC (network interface card)
also known as a network adapter card, is used to provide the physical interface between a computer and the cabling used for connectivity
SDN (software defined networking)
sets up a network virtually via the cloud. The SDN replaces the functionality of the router in a network
What are the two operating frequencies for wi-fi?
2.4 Ghz and 5 Ghz.
2.4 Ghz (operating frequency for wi-fi)
This relatively low frequency (compared with 5 GHz) has a greater transmission range because it passes through objects such as walls and floors better.
On the negative side, throughput is slower and it is an open frequency range that other devices use. Devices like cordless phones and microwave ovens can interfere with it.
5 Ghz (operating frequency for wifi)
At this higher frequency, throughput is faster. On the negative side, the transmission range is shorter as the signal is attenuated by objects such as walls and floors.
What’s the difference between 2.4 ghz and 5 ghz for wifi frequency?
While 2.4 ghz has a greater transmission range and passes through floors and walls better, 5 ghz doesn’t and has a shorter transmission range.
5 ghz has a faster speed, while 2.4 ghz is slower because it’s an open frequency and phones/microwaves interfere with it.
2.4 has 14 channels (11 available in the US) and 5 ghz has 25 (20 mhz) channels that we never have to set or change (we use 24 for wifi).
They’re also both unlicensed frequencies, which means anyone could use them (interference/eavesdropping could happen).
What did the FCC (Federal Communications Commission) with the communication channels?
defined 14 different 22 MHz communications channels but only allows for the use of the first 11 channels.
What is the 802.11 specification for wifi?
part of the IEEE 802 wireless networking standards. It is used for Wi-Fi communications. The (different letters) all use the ethernet protocol and carrier sense multiple access with collision avoidance (CSMA/CA) media access method. The main characteristics that differentiate them are their operating frequencies, theoretical maximum data speed, and throughput.
What are the 802.11 standards, what are their frequencies, throughput, and range?
a—5 GHz frequency, 54 Mbps maximum throughput, 120 meters range
b—2.4 GHz frequency, 11 Mbps maximum throughput, 140 meters range
g—2.4 GHz frequency, 54 Mbps maximum throughput, 140 meters range
n—5/2.4 GHz frequency, 600 Mbps maximum throughput, 250 meters range
ac (Wi-Fi 5)—5 GHz frequency, 6.5 Gbps maximum throughput, 140 meters range
ax (Wi-Fi 6)—5/2.4 GHz frequency, 9.6 Gbps maximum throughput, 140 meters range
long-range fixed wireless connection
point-to-point wireless technology that employs the use of directional antennas to send and receive network signals usually from 10 to 20 km.
Power can be transmitted via long-range fixed wireless and is commonly known as wireless power transfer (WPT). Power is generated by the transmitting station and sent via microwave or laser light to the receiver who turns the transmission back into electricity.
What are licensed frequencies in the U.S.?
Frequencies whose use is granted by the FCC (Federal Communications Commission).
unlicensed frequencies
frequencies that can be used by anyone, such as 2.4 and 5 GHz. The common use of these frequencies, however, often causes interference and can create susceptibility to eavesdropping.
WPT (Wireless Power Transfer)
Power can be transmitted via long-range fixed wireless and is commonly known as wireless power transfer (WPT). Power is generated by the transmitting station and sent via microwave or laser light to the receiver who turns the transmission back into electricity.
WPT (Wireless Power Transfer)
Power can be transmitted via long-range fixed wireless and is commonly known as wireless power transfer (WPT). Power is generated by the transmitting station and sent via microwave or laser light to the receiver who turns the transmission back into electricity.
RFID (radio frequency identification)
uses a radio signal to send information from an RFID tag with identifying information. This is commonly used to streamline the inventory of tracking applications.
What’s the difference between a client application and a server application?
Client applications request services from a server application.
What’s a server?
not necessarily a stand-alone piece of hardware. A server is usually a process running in memory on a networked system that responds to requests from a remote client system.
DNS (Domain Name System)
resolve hostnames to IP addresses.
Two public DNS servers are needed for an enterprise to host a website, with one DNS server acting as redundancy. Records of hostname IP address sets are held in a zone file. The zone file maintains records of hostname-to-IP address mappings and contains information such as the name of the server or computer, internet protocol address, record type, computer address, and comments.
If the DNS address is not located in the zone file, it requests the information from a higher-level DNS server called the root server.
DHCP (Dynamic Host Configuration Protocol)
provides IP configuration information, such as an IP address, subnet mask, default gateway, and DNS server address, automatically to clients.
The scope of a DHCP server contains the information that is permitted to be shared with a client.
fileshare / file server
central repository for the storage, management, and access of network files.
A network can also use network-attached storage (NAS) for a file server
print server
server that manages print requests and connects printers to a network
mail server
responsible for sending, receiving, and managing emails. A mail server must be running a specialized server package, such as Microsoft Exchange, Sendmail, Postfix, or Exim, to be considered a mail server.
syslog
responsible for collecting information obtained through system monitoring, such as login events or errors.
Messages compiled in a syslog server include the facility code, the severity level, and a textual description of the logged events.
Syslog servers are composed of three primary components: the listener, the database, and the management and filtering software.
web servers
listens for incoming requests.
The requests are executed by the web server and provide the requested content, including text, images, videos, and the running of scripts.
Common web server platforms include Microsoft’s Internet Information Services (IIS) and Apache.
authentication, authorization, and accounting (triple A or AAA)
access control server that acts as a gatekeeper for critical network components.
AAA servers are also known as domain controllers.
Examples of AAA servers include remote access service (RAS), Remote Authentication Dial-In User Service (RADIUS), Terminal Access Controller Access-Control System Plus (TACACS+), and Kerberos.
spam gateway / antispam gateway
internet appliance whose purpose is to block malicious emails from accessing the networ
Unified Threat Management (UTM)
acts to centralize security management on a network.
UTM typically provides packeting filtering and inspection, IPS, gateway antimalware, spam blocking, malicious website blocking, and application control.
proxy servers
makes requests for resources on behalf of a client. The proxy server acts as an intermediary between the client and the target server.
What’s the difference between a legacy and an embedded system?
Legacy systems are older systems that for one reason or another have not been updated. It is usually due to essential applications that will not run on the updated platform.
Embedded systems are devices other than computers that have computer technology running within. Like legacy systems, these may not be able to stay updated
Supervisory Control and Data Acquisition (SCADA)
example of a critical legacy system category.
A SCADA system is a high-level management system used to control manufacturing machines and processes, manage large-scale infrastructure settings, and run building components.
internet of things (IoT) device
connects to the network through a central controller or coordinating device. Common examples of IoT devices include smart devices such as thermostats and home automation and security devices.
What steps do you take to set up a SOHO (small office/home office)?
- Understand relevant regulations.
- Make a map.
- Locate the server(s).
- Identify client computer locations.
- Locate network resources.
- Determine user connectivity type.
- Designate additional connectivity options if needed.
What is the concept of IP addressing?
assignment of a unique device identifier on a local network or the internet. The IP address is responsible for managing logical network addresses.
IVP4 Addressing
32-bit hierarchical address that identifies a host on a network and is typically written in dotted-decimal notation.
The 32-bit address is divided into 4 bytes, or octets, containing 8 bits each (ex: 192.168.10.55).
IPv4 addresses are divided into designated classes, A, B, C, D, E, and F, based on the first 3 bits of the IP address. IPv4 addresses are finite and are running out.
Private addresses—A private IP address is not routable on the internet.
Class A private address range: 10.0.0.0–10.255.255.255
Class B private address range: 172.16.0.0–172.31.255.255
Class C private address range: 192.168.0.0.–192.168.255.255
Public addresses—Public addresses are routable on the internet. Public addresses are purchased and only one computer can hold any given public address at a time.
IPV6 Addresses
128-bit addresses expressed in hexadecimal notation and are composed of eight 16-bit fields separated by colons (ex: 2001:0db8:3c4d:0012:0000:0000:1234:56ab, which can be reduced to 2001:db8:3c4d:12::1234:56ab)
What is APIPA (Automatic Private IP Addressing) and what does it do?
assigns an IP address to a device that was not assigned a static or dynamic IP address.
The address will be in the 169.254.0.0 network. This is generally not useful, other than being an indication that the device failed to get an IP address through normal means.
These addresses are also referred to as link-local addresses.
What’s the difference between static and dynamic IP addresses?
Dynamic addresses are automatically assigned by a router or DHCP server. Static addresses are set manually by a user or administrator.
A device that’s set manually (statically) by someone will keep that address until the configuration is changed; a dynamic address is assigned to a device every time it joins the network.
gateway router
router that connects your network to another network, typically the Internet.
When configuring a device on the network, you specify the internal IP address of the gateway as a default destination to send traffic.
A - DNS record type
common DNS record type that signifies the host record is an IVP4 address.
AAAA - DNS address
pronounced “quad A”
record DNS type that signifies the host record is an IVP6 address.
MX - Mail Exchanger
common DNS record type that signifies the host record is the name of address of an email server.
Text (TXT)
common DNS record type that signifies that the host record is a text record for human-readable or machine-readable data.
DKIM - DomainKeys Identified Mail
type of spam management that authenticates using encryption through a public-private key pair.
SPF - Sender Policy Framework
spam management that authenticates an email server based on its IP address.
DMARC - Domain based Message Authentication, Reporting and Conformance
type of spam management that combines DKIM and SPF in one framework
offers more control over what the user can do with spam email.
If you want to ensure that a device gets a special IP address, you can -
configure a DHCP reservation in the DHCP server.
Lease
temporary IP configuration assigned by the DHCP server to a client.
typically includes an IP address, subnet mask, default gateway, and DNS server address.
Reservation - ip address
reserving of an IP address for a specific client based on the client’s MAC address and is primarily used for devices that require a static IP address.
scope
information provided outside the IP address and the subnet mask issued by the DHCP server, such as the default gateway, DNS server address, or domain name.
virtual LAN (VLAN)
logical subnet, typically configured on a switch, that acts as a separate subnet.
Without VLANs, every device connected to a switch would be on the same subnet.
By configuring VLANs on the switch, you can have devices on that one switch in different subnets or VLANs.
VPN - Virtual Private Network
encrypted connection between two networks or between a host and a network. When a host connects to a network over a VPN, it is assigned a separate IP address that is in the network’s address range.
satellite - connection
employs the use of satellites to achieve connectivity.
Slower than wired broadband connections; require a satellite disk.
Weather and misalignment can affect connectivity
fiber internet connection
type of wired connection that uses a fiber-optic cable made of thin flexible glass or plastic fiber surrounded by a rubberized outer sheath to send data via light signals. Fiber offers fast data transmission. There are two types of fiber varieties: single-mode fiber (SMF) and multimode fiber (MMF).
cable connection
type of wired connection that uses a cable; either coaxial/coax or twisted pair for data transmission.
Coax and twisted pair cables use different connector types and cable specifications.
DSL (digital subscriber line)
type of wired connection that uses existing phone lines paired with a DSL modem to provide internet service.
cellular connection
wireless connection type that uses a provider’s cellular network for connectivity
WISP - wireless internet service provider
wireless connection type in which an internet service provider (ISP) offers connectivity using wireless technology. WISP connections are fixed point-to-point connections.
Local Area Network (LAN)
collection of devices connected to one another in one physical area, such as an office building, and can be small or large.
WAN - wide area network
network that covers a large geographical area and is composed of multiple LANs. The internet is a WAN.
PAN - personal area network
composed of primarily Bluetooth-connected devices.
MAN - metropolitan area network
network larger than a LAN but smaller than a WAN and limited to a smaller geographical area, such as a city or a campus.
SAN - storage area network
network area composed of storage devices
WLAN - wireless local area network
LAN in which the connections are wireless rather than wired
What is a crimper used for?
used to connect a connector to a cable. It is not usually practical to use cables of a fixed length. It is also easier to run cable without the connectors on it. So, the cable is run and cut to the desired length, and then the connector is crimped on using a crimper. There are different types of crimpers for ethernet, coaxial, and fiber-optic cables.
cable stripper
used to remove the insulation from the end of a cable before the connector is crimped onto it.
wi-fi analyzer
used to design, optimize, or troubleshoot a Wi-Fi network. This device is used to show strong and weak spots in wireless coverage. It is a way to visualize Wi-Fi network coverage.
punchdown tool
connects the exposed ends of a wire into a wiring harness.
loopback plug
special cable that is wired to transmit and receive on a single connector. There are loopback plugs for different types of connectors, like USB or ethernet, for testing network interface cards (NICs).
cable tester
used to certify that the cable meets the standards of the wiring code and to ensure it can be used for communication. It will identify broken wires or missing pin connections.
network TAP
hardware device that creates a copy of network traffic for use by monitoring devices without interfering with network traffic. A network TAP can be easily moved from location to location to identify problems.
