CFB Final Exam: Computer Networks and Security

Network Fundamentals

• Underlying architectures must address four basic characteristics to meet user expectations: scalability, reliability, performance, and security.
• The OSI model consists of seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

OSI Model Layers

• Physical Layer: defines physical means of data transmission
• Data Link Layer: provides error-free transfer of data frames between nodes
• Network Layer: routes data between nodes on different networks
• Transport Layer: provides reliable data transfer between devices
• Session Layer: establishes, manages, and terminates connections
• Presentation Layer: translates data into a format understandable by the receiving device
• Application Layer: provides services and interfaces for applications to communicate

Data Link Layer Sublayers

• Media Access Control (MAC) sublayer: controls access to the network
• Logical Link Control (LLC) sublayer: provides error-free transfer of data frames

Network Topologies

• Physical WAN topologies: Point-to-Point, Point-to-Multipoint, and Hub-and-Spoke
• Logical topologies: Bus, Star, Ring, Mesh, and Tree

Migration Techniques

• Three categories: Phased Migration, Parallel Migration, and Big-Bang Migration

IPv4 vs IPv6

• IPv4: 32-bit address, limited address space, uses NAT
• IPv6: 128-bit address, increased address space, improved security

Malware

• Three types: Viruses, Worms, and Trojans

Firewalls

• Four types: Network-based Firewalls, Host-based Firewalls, Application-based Firewalls, and Stateful Firewalls

Network Layer Operations

• Four basic processes: Routing, Addressing, Congestion Control, and Fragmentation

Networking Terminology

• Latency: delay between sending and receiving data
• Bandwidth: amount of data transmitted per unit time
• Throughput: actual amount of data transferred
• Encoding: converting data into a suitable format
• Signaling: control information used to manage data transmission

Cables and Wireless Connections

• Types of cables: Coaxial, Twisted Pair, and Fiber Optic
• Characteristics of cables: bandwidth, distance, and interference
• Limitations of wireless connections: security, interference, and range

Communication Modes

• Half-Duplex: data transmission in both directions, but not simultaneously
• Full-Duplex: data transmission in both directions simultaneously

Remote Access Protocols

• Telnet: insecure, uses plain text, and uses TCP
• SSH: secure, uses encryption, and uses TCP

Application Layer Protocols

• DNS: translates domain names to IP addresses
• DHCP: dynamically assigns IP addresses to devices

IPv4 Network Transmission

• Three ways of transmission: Unicast, Multicast, and Broadcast

IPv4 vs IPv6 Transition

• IP vs Tunneling: IPv6 packets encapsulated in IPv4 packets for transmission

Transport Layer Protocols

• TCP: connection-oriented, reliable, and error-checked
• UDP: connectionless, fast, and error-tolerant

This final exam covers key concepts in computer networks, including the OSI model, protocols, topologies, and WAN topologies, as well as security topics such as malware, firewalls, and IPv4 vs IPv6.