Exam Objectives Flashcards
(1.1) Explain concepts related to the Open Systems Interconnection (OSI) reference model.
Please Do Not Throw Sausage Pizza Away
Application - The closest layer to the user; provides application services.
Presentation - Encrypts, encodes and compresses usable data.
Session - Establishes, manages, and terminates sessions between end nodes.
Transport - Transmits data using transmission protocols including TCP and UDP.
Network - Assigns publicly accessible IP addresses to interfaces and determines the best routes through different networks.
Data Link - Assigns local addresses to interfaces, delivers information locally, MAC method.
Physical - Encodes signals, cabling and connectors, physical specifications.
(1.3) Summarize cloud concepts and connectivity options.
Scalability vs Elasticity
Scalability focuses on the ability to handle increasing workload by adding resources.
Elasticity embodies the dynamic responsiveness to fluctuating demands, scaling resources up or down as needed.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Memorize ports and services.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Internet Protocol Types:
Internet Control Message Protocol (ICMP)
A network layer protocol used by network devices to diagnose network communication issues.
The primary purpose of ICMP is for error reporting.
A secondary use of ICMP protocol is to perform network diagnostics; the commonly used terminal utilities traceroute and ping both operate using ICMP.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Internet Protocol Types:
Transmission Control Protocol (TCP)
A fundamental internet protocol that ensures reliable data transmission between devices on a network by establishing a connection and managing the flow of data packets, guaranteeing their delivery in the correct order and without errors, making it the primary protocol used for most internet applications like web browsing, email, and file transfer.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Internet Protocol Types:
User Datagram Protocol (UDP)
A communication protocol used in computer networks that allows for fast data transmission by not establishing a connection beforehand, making it ideal for time-sensitive applications like online gaming, video streaming, and voice over IP (VoIP) where occasional packet loss is acceptable and speed is prioritized over guaranteed delivery.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Internet Protocol Types:
Generic Routing Encapsulation (GRE)
A protocol for encapsulating data packets that use one routing protocol inside the packets of another protocol. While GRE can create a tunnel, it does not inherently encrypt the data within the encapsulated packet, so additional security measures may be needed for sensitive information.
For instance, suppose a company needs to set up a connection between the local area networks (LANs) in their two different offices. Both LANs use the latest version of the Internet Protocol, IPv6. But in order to get from one office network to another, traffic must pass through a network managed by a third party — which is somewhat outdated and only supports the older IPv4 protocol.
With GRE, the company could send traffic through this network by encapsulating IPv6 packets within IPv4 packets. Referring back to the analogy, the IPv6 packets are the car, the IPv4 packets are the ferry, and the third-party network is the water.
Example in networking would be creating a virtual “tunnel” between two geographically separated branch offices over the internet, where each office’s private network traffic is encapsulated in a GRE packet and sent across the public internet to the other office, effectively allowing them to communicate as if they were directly connected, even though they are not physically linked
(1.4) Explain common networking ports, protocols, services, and traffic types.
Internet Protocol Security (IPSec):
- Authentication Header (AH)
- Encapsulating Security Payload (ESP)
- Internet Key Exchange (IKE)
IPSec - A set of protocols that encrypts and authenticates data packets to create secure connections over a network. It’s used to protect data as it travels over the internet, especially in VPNs.
IKE - Create secure tunnels to protect the data. The two sites will identify each other and negotiate the parameters for authentication and encryption methods.
AH - IPsec protocol that offers authentication and integrity.
ESP - IPsec protocol that offers authentication and integrity and encryption.
Public key locks the data as it is sent and private key is used to unlock when received.
(1.4) Explain common networking ports, protocols, services, and traffic types.
Traffic types:
- Unicast
- Multicast
- Anycast
- Broadcast
Unicast - One to one.
Multicast - Data is sent to a group of recipients.
Anycast - The communication that is developed with IPv6. The traffic is received by the nearest receiver in a group of the receivers that has the same IP.
Broadcast - Data is sent to all recipients in a network.
(1.5) Compare and contrast transmission media and transceivers.
Transceivers:
Fibre Channel
A high-speed data transfer protocol providing in-order, lossless delivery of raw block data. Fibre Channel is primarily used to connect computer data storage to servers in storage area networks (SAN) in commercial data centers.
(1.5) Compare and contrast transmission media and transceivers.
Form Factors:
Small Form-factor Pluggable (SFP)
Quad Small Form-factor Pluggable (QSFP)
SFP - A compact, hot-swappable transceiver module used to connect network devices like switches and routers to fiber optic or copper cables.
QSFP - A type of compact, hot-swappable transceiver that can simultaneously transmit data across four separate channels, essentially providing significantly higher bandwidth compared to a standard SFP (Small Form-factor Pluggable) by offering four times the data capacity in a single port
(1.5) Compare and contrast transmission media and transceivers.
Connector types:
- Subscriber connector (SC)
- Local connector (LC)
- Straight tip (ST)
- Multi-fiber push on (MPO)
- Registered jack (RJ)11
- RJ45
- F-type
- Bayonet Neill–Concelman (BNC)
SC - A type of fiber optic connector commonly used in telecommunications and data centers, known for its push-pull latching mechanism, square shape, and ease of use.
LC - A small, popular type of fiber optic connector known for its compact size and latching mechanism, making it ideal for high-density applications like data centers where space is limited; it’s considered one of the most commonly used fiber optic connectors today.
ST - A type of fiber optic connector that uses a bayonet-style locking mechanism to secure the connection, essentially meaning you twist to connect and disconnect the cable; it’s considered one of the older, widely used fiber optic connector types known for its durability and ease of use.
MPO - A type of fiber optic connector called an “MPO” (Multi-Fiber Push-On), which allows multiple optical fibers to be connected through a single connector, enabling high-density cabling and supporting high-speed data transmission, typically used in data centers and telecommunication networks where space is limited and large bandwidth is required.
RJ11 - A type of connector commonly used for telephone cables.
RJ45 - A wired connection that uses RJ-45 connectors to connect devices to a local area network (LAN). RJ-45 connectors are the most common type of connector used for Ethernet cables.
F type - A threaded, compression-type connector used to connect coaxial cables for networking. They are commonly used for cable television, satellite television, and internet connections.
BNC - A type of coaxial cable connector, commonly used for video transmission and early computer networks, that utilizes a bayonet-style locking mechanism for a quick and secure connection; it’s known for its reliability in transmitting high-frequency signals with minimal signal loss.
(1.6) Compare and contrast network topologies, architectures, and types.
Spine and leaf
A network architecture where “spine” switches act as the network core, interconnecting all the “leaf” switches which are the access points connecting to servers and other end-user devices, essentially creating a two-tiered structure designed for high scalability and low latency in data centers; the spine layer handles routing while the leaf layer provides access to the network.
(1.6) Compare and contrast network topologies, architectures, and types.
Three-tier hierarchical model
Core:
- The backbone of the network, responsible for high-speed data transmission between different distribution layers, typically with minimal processing to ensure fast data transfer.
Distribution:
- Communication between access switches.
- Acts as a bridge between the access layer and the core layer, performing routing, filtering, and policy management for traffic flow between different network segments
Access:
- This is the layer where end-user devices like computers and printers connect to the network; it handles user authentication and basic network access.
(1.7) Given a scenario, use appropriate IPv4 network addressing.
Public vs. private:
APIPA
IPv4. A feature that allows devices to assign themselves IP addresses when a DHCP server is unavailable. It’s a feature of Microsoft Windows operating systems.
(1.7) Given a scenario, use appropriate IPv4 network addressing.
Public vs. private:
RFC 1918
A set of rules that defines IP addresses for private networks. It’s a record from the Internet Engineering Task Force (IETF).
10.0.0.0/8 or 10.0.0.0 – 10.255.255.255
172.16.0.0/12 or 172.16.0.0 – 172.31.255.255
192.168.0.0/16 or 192.168.0.0 – 192.168.255.255
(1.7) Given a scenario, use appropriate IPv4 network addressing.
Public vs. private:
Loopback/local host
A Loopback Address, also known as localhost, refers to an internal address that directs back to the local system. In IPv4, the loopback address is 127.0.0.1.
(1.7) Given a scenario, use appropriate IPv4 network addressing.
Subnetting:
Variable Length Subnet Mask (VLSM)
Classless Inter-domain Routing (CIDR)
Classful addressing is IANA/RIRs assigning IP space from Class A, B, or C blocks (legacy).
Classless or CIDR is IANA/RIRs assigning IP space in any size block, as required (modern standard).
FLSM mandates that every IP subnet within your deployment be the same size (legacy).
VLSM allows any IP subnet within your deployment to be any size (modern standard).
(1.8) Summarize evolving use cases for modern network environments.
Go over the deck named 009.
(2.1) Explain characteristics of routing technologies.
Dynamic routing:
Border Gateway Protocol (BGP)
Enhanced Interior Gateway
Routing Protocol (EIGRP)
Open Shortest Path First (OSPF)
BGP:
Hybrid.
Exterior gateway protocol.
Connects different AS.
EIGRP:
Hybrid.
Mostly Cisco-centric.
Easy to setup.
Converge quickly.
Loop free.
Efficient discovery of neighbor routers.
Sends updates over minimum bandwidth traffic.
Commonly used in networking to efficiently route traffic within a single autonomous system (AS), particularly in scenarios where fast convergence, load balancing, and flexible metric calculations are needed, making it a popular choice for large, complex internal networks
Feasible successor in EIGRP - Backup route in case of primary route failure.
OSPF:
A common interior gateway protocol.
Used within a single autonomous system. AS = where you have the complete control of systems.
Available on many different manufacturers.
Link-state protocol.
Each link has a cost which includes throughput, reliability, roundtrip time.
Lowest cost and fastest route wins.
(2.1) Explain characteristics of routing technologies.
Route Selection:
Prefix length
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(2.3) Given a scenario, select and configure wireless devices and technologies.
Channels:
Regulatory impacts:
802.11h
802.11h is a wireless standard that helps reduce interference and power consumption. It was added to the IEEE 802.11 standard in 2003.
Dynamic Frequency Selection (DFS): Automatically switches channels when other devices are detected
Transmit Power Control (TPC): Lowers the radio frequency output of wireless devices
(2.3) Given a scenario, select and configure wireless devices and technologies.
Frequency options:
Band steering
A feature on dual-band Wi-Fi routers and access points that automatically directs devices to the most suitable frequency band (either 2.4 GHz or 5 GHz) based on their capabilities, effectively reducing congestion on the 2.4 GHz band and optimizing network performance by encouraging devices to use the faster 5 GHz band when possible; essentially, it helps devices choose the best available band for their connection needs, improving user experience.
(2.3) Given a scenario, select and configure wireless devices and technologies.
Service set identifier (SSID):
Basic service set identifier (BSSID)
BSSID is a technical identifier based on the MAC (Media Access Control) address of the AP’s wireless adapter.
(2.3) Given a scenario, select and configure wireless devices and technologies.
Network types:
Infrastructure
Meaning all wireless devices connect to the network by going through a single point, like a router, rather than directly to each other; this is the most common type of wireless network setup, as opposed to an “ad hoc” network where devices connect directly with each other without a central AP.
(2.4) Explain important factors of physical installations.
Important installation implications:
Port-side exhaust/intake
Refers to a switch or device configuration where the hot air is expelled from the side where the network ports are located, meaning cool air enters from the opposite side, while “port-side intake” indicates that cool air enters through the port side and hot air exits from the other side; essentially describing the direction of airflow relative to the network ports on a device.
(3.2) Given a scenario, use network monitoring technologies.
Methods:
SNMP:
Community strings
An SNMP community string is a means of accessing statistics stored within a router or other device. Sometimes referred to simply as a community string or an SNMP string, it comprises the user credential—ID or password—delivered alongside a GET request.
There are three types of community string:
Read-only – The read-only community string enables a device to extract read-only data from another device.
Read-write – The read-write community string is used to extract data and alter device configurations.
SNMP trap – The SNMP trap community string is used when an SNMP trap is sent by a device.
(3.4) Given a scenario, implement IPv4 and IPv6 network services.
Name resolution:
DNS:
Domain Name Security Extensions (DNSSEC)
DNS over HTTPS (DoH) and DNS over TLS (DoT)
Domain Name Security Extensions (DNSSEC):
It uses digital signatures to verify the origin and integrity of DNS data, allowing users to trust that the IP address they are being directed to is the correct one for the domain they entered.
DNS over HTTPS (DoH):
a protocol that encrypts Domain Name System (DNS) traffic by sending DNS queries through a secure HTTPS connection, essentially hiding the websites a user is trying to access from potential eavesdroppers and improving online privacy and security by preventing the interception of DNS requests.
DNS over TLS (DoT):
a protocol that encrypts Domain Name System (DNS) queries using the Transport Layer Security (TLS) standard, essentially protecting the privacy of your internet activity by preventing eavesdroppers from seeing which websites you are trying to access by obscuring the DNS requests sent from your device to a DNS resolver.
(3.4) Given a scenario, implement IPv4 and IPv6 network services.
Name resolution:
DNS:
Zone types:
Forward
Reverse
A “forward DNS zone” translates domain names to IP addresses, while a “reverse DNS zone” translates IP addresses back to domain names.
(3.4) Given a scenario, implement IPv4 and IPv6 network services.
Name resolution:
Hosts file
A plain text file on a computer that acts as a local, manually-managed Domain Name System (DNS) by mapping hostnames (like “www.google.com”) to their corresponding IP addresses, allowing the computer to resolve website names without needing to query a remote DNS server; essentially acting as a local cache for specific domain name resolutions.
(3.4) Given a scenario, implement IPv4 and IPv6 network services.
Time protocols:
NTP
Precision Time Protocol (PTP)
Network Time Security (NTS)
NTP” stands for Network Time Protocol, “PTP” stands for Precision Time Protocol, and “NTS” stands for Network Time Security, all of which are used to synchronize clocks across devices on a network, with PTP offering the highest accuracy for applications requiring precise timing, while NTP is more widely used for general time synchronization and NTS adds security features to NTP communication by encrypting time data.
(3.5) Compare and contrast network access and management methods.
In-band vs. out-of-band management
In-band management - refers to managing network devices using the same network infrastructure as regular data traffic.
Out-of-band management - uses a separate, dedicated network to manage devices, allowing access even when the primary network is down, providing greater reliability and security during outages.
(4.1) Explain the importance of basic network security concepts.
Common security terminology:
Risk
Vulnerability
Exploit
Threat
Risk - the potential for damage or loss that could occur if a threat successfully exploits a vulnerability.
Vulnerability - a weakness or flaw in a system that can be exploited.
Exploit - the actual code or method used to take advantage of that vulnerability.
Threat - the potential danger or malicious actor that could use the exploit to cause harm by leveraging the vulnerability.
(4.3) Given a scenario, apply network security features, defense techniques, and solutions.
Zones:
Screened subnet
A separate, isolated network segment, often called a “demilitarized zone (DMZ)”, that acts as a buffer between a public network (like the internet) and a private internal network, providing an additional layer of security by filtering traffic and only allowing controlled access to public-facing servers hosted within the DMZ.
(5.2) Given a scenario, troubleshoot common cabling and physical interface issues.
Interface issues:
Cyclic redundancy check (CRC)
A mathematical algorithm used to detect errors in transmitted data by calculating a checksum value from the data, which is then appended to the data and verified by the receiver to ensure the data integrity during transmission.
(5.2) Given a scenario, troubleshoot common cabling and physical interface issues.
Interface issues:
Port status:
Error disabled
A switch port has been automatically shut down by the device due to detecting a critical error condition, like a faulty cable, incorrect duplex settings, or a violation of port security, effectively preventing any traffic from being sent or received on that port until the issue is addressed and the port is manually re-enabled.
(5.2) Given a scenario, troubleshoot common cabling and physical interface issues.
Interface issues:
Port status:
Suspended
Indicates that a network port is currently not actively participating in a port channel due to a configuration mismatch or lack of communication with the other ports it is supposed to be bundled with, usually triggered by the Link Aggregation Control Protocol (LACP) when it detects an inconsistency with the peer device.
DLP
Data Loss Prevention, a cybersecurity strategy that monitors and protects an organization’s data. DLP helps prevent unauthorized access, use, or transmission of sensitive data.
