CSCI 291 Quiz 2a

Study Guide for Networking Topics

1. Common Cable Types

• Household Cables:

  • RJ-45: Used for Ethernet networking (LAN, WAN). Connects routers, computers, and switches.

  • RJ-11: Used for telephone lines and low-speed DSL connections.

  • UTP (Unshielded Twisted Pair): Used for LAN connections. Characteristics include twisted copper wires to minimize electromagnetic interference (EMI), less expensive, and flexible.

  • Coaxial Cable: Used for cable TV and some internet connections. Provides higher bandwidth than UTP.

• Business Cables (Medium to Large):

  • Fiber Optic Cables: Used for high-speed internet connections (e.g., T3, OC3, OC12). Characteristics include high bandwidth, long-distance transmission, and immunity to EMI.

  • Ethernet Cables (Cat 5e, Cat 6, Cat 7): Used for high-speed LAN connections. Cat 6 supports up to 10 Gbps, while Cat 7 supports up to 10 Gbps with higher bandwidth.

  • DSL/Cable: Used for smaller businesses. DSL uses telephone lines, while cable uses coaxial cables.

2. Characteristics of Network Devices

• Hub:

  • Connects multiple devices on a LAN.

  • Broadcasts data to all ports, leading to potential data collisions.

  • Inexpensive but inefficient for large networks.

• Repeater:

  • Amplifies signals to extend network range.

  • Used to strengthen signals in both wired and wireless networks.

• Switch:

  • Connects multiple devices on a LAN.

  • Sends data only to the intended recipient, reducing collisions.

  • More efficient than hubs.

• Router:

  • Connects multiple networks (e.g., LAN to the internet).

  • Routes data packets between networks using IP addresses.

  • Provides security features like firewalls and encryption.

3. Wireless Technologies

• Wi-Fi:

  • Used for wireless internet access in homes, offices, and public spaces.

  • Operates on 2.4 GHz and 5 GHz frequencies.

  • Standards include 802.11a/b/g/n/ac/ax (Wi-Fi 6).

• Bluetooth:

  • Used for short-range wireless communication between devices (e.g., headphones, keyboards).

  • Operates on 2.4 GHz frequency.

  • Low energy consumption, suitable for IoT devices.

• ZigBee:

  • Used for smart home automation (e.g., lights, security systems).

  • Operates on low-energy radio frequencies.

  • Forms mesh networks for reliable communication.

4. Common Communication Protocols

• FTP (File Transfer Protocol): Used for transferring files between a client and server (port 21).

• Telnet: Used for remote access to devices (insecure, replaced by SSH).

• SSH (Secure Shell): Secure remote access and file transfer (port 22).

• SMTP (Simple Mail Transfer Protocol): Used for sending emails (port 25).

• DNS (Domain Name System): Translates domain names to IP addresses (port 53).

• HTTP (Hypertext Transfer Protocol): Used for web browsing (port 80).

• HTTPS (HTTP Secure): Secure version of HTTP (port 443).

• POP3 (Post Office Protocol): Used for retrieving emails from a server (port 110).

• IRC (Internet Relay Chat): Used for real-time text messaging (ports 6660-6669).

5. Ports and IP Addresses

• Number of Ports: 65,536 ports (0-65535).

  • Well-known ports: 0-1023 (e.g., HTTP on port 80).

  • Registered ports: 1024-49151.

  • Dynamic/Private ports: 49152-65535.

• Public vs. Private IP Addresses:

  • Public IP: Visible on the internet, assigned by ISPs.

  • Private IP: Used within local networks (e.g., 192.168.x.x).

• IPv4:

  • 32-bit address (e.g., 192.168.1.1).

  • Limited address space (4.3 billion addresses).

• CIDR (Classless Inter-Domain Routing):

  • Allows efficient allocation of IP addresses.

  • Replaces classful addressing (A, B, C).

  • Example: 192.168.1.0/24.

6. Packets and Headers

• Packet: A small segment of data sent over a network.

  • Header: Contains metadata (source/destination IP, error-checking, sequencing).

  • Payload: The actual data being transmitted.

  • Trailer: Contains error-checking information (e.g., CRC).

7. Network Utility Commands

• ipconfig: Displays network configuration (IP address, subnet mask, default gateway).

• ping: Tests connectivity to a host by sending ICMP Echo Request packets.

• tracert: Maps the path packets take to reach a destination.

• netstat: Displays active connections, listening ports, and network statistics.

• nslookup: Queries DNS to resolve domain names to IP addresses.

8. Security Concepts

• VPN (Virtual Private Network):

  • Encrypts internet traffic and masks the user's IP address.

  • Used for secure remote access and bypassing geo-restrictions.

• Firewall:

  • Monitors and controls incoming/outgoing network traffic.

  • Protects against unauthorized access and cyber threats.

• Proxy Server:

  • Acts as an intermediary between a user and the internet.

  • Used for anonymity, content filtering, and caching.

9. OSI Model

• 7 Layers:

  1. Physical: Transmits raw bits over a physical medium (e.g., cables, Wi-Fi).

  2. Data Link: Defines the format of data on the network (e.g., MAC addresses).

  3. Network: Routes data between devices using IP addresses.

  4. Transport: Ensures reliable data transfer (e.g., TCP, UDP).

  5. Session: Manages connections between applications.

  6. Presentation: Translates data between applications and the network (e.g., encryption).

  7. Application: Provides network services to end-users (e.g., HTTP, FTP).

10. Cloud Computing

• Definition: Delivery of computing services (e.g., storage, servers) over the internet.

• AWS Cloud Security Foundations Course Objectives:

  • Understand cloud security concepts.

  • Learn to secure AWS resources.

  • Implement identity and access management (IAM).

11. Cyberattack Uses of Commands

• ipconfig/ifconfig: Can be used to gather network information for reconnaissance.

• traceroute: Can map network topology for potential attacks.

• nslookup: Can be used for DNS spoofing or reconnaissance.

• ping: Can be used for ICMP flood attacks (ping of death).

This study guide covers the key topics from the PDF, providing a concise overview of networking concepts, protocols, and tools.