Week 12: Basic Network Config in Cisco Packet Tracer - M199205zn/Datacomm-CS3 GitHub Wiki

Lesson: Understanding Basic Network Configuration in Cisco Packet Tracer

Lesson Overview

This lesson covers fundamental networking concepts using Cisco Packet Tracer. Students will learn about network devices, IP addressing, basic configuration commands, and troubleshooting techniques. The lesson also highlights common networking protocols and best practices for ensuring network connectivity.

Learning Objectives

By the end of this lesson, students should be able to:

Identify the correct cables and devices used in a network setup.
Understand basic IP addressing and subnet masks.
Configure routers and switches using essential CLI commands.
Verify network connectivity and troubleshoot common network issues.
Explain the role of networking protocols like ICMP, DHCP, and TCP/IP.

Lesson Content

1. Network Devices and Connectivity

Computers (PCs): End-user devices that send and receive data in a network.
Switches: Connect multiple devices within the same network and forward data efficiently.
Routers: Direct network traffic between different networks and manage IP addressing.
Cables:
- Straight-through cable (PC to Switch connections).
- Crossover cable (Switch to Switch or PC to PC connections).
- Console cable (Used to configure a router or switch via a terminal session).

2. IP Addressing and Subnetting

IPv4 Addressing: A unique numerical label assigned to each device in a network (e.g., 192.168.1.2).
Subnet Mask: Determines which portion of an IP address belongs to the network and which to the host.
Default Gateway: The router’s IP address that serves as the access point for communication with other networks.
Common Subnet Masks:
- Class C: 255.255.255.0 (supports up to 254 hosts).
- Class B: 255.255.0.0 (supports larger networks).
- Class A: 255.0.0.0 (used in very large networks).

3. Basic Router and Switch Configuration Commands

Entering global configuration mode:
```
configure terminal
```

Assigning an IP address to an interface:

interface FastEthernet 0/0
ip address 192.168.1.1 255.255.255.0
no shutdown

Viewing interface status:
```
show ip interface brief
```
Testing network connectivity:
```
ping [destination IP]
```
Saving configuration:
```
write memory
```

4. Network Verification and Troubleshooting

Common verification commands:
- ping: Tests connectivity between devices.
- tracert: Traces the path a packet takes to a destination.
- show running-config: Displays the current router configuration.
- ipconfig: Shows the IP configuration of a PC.
Troubleshooting Steps:
- Check for IP conflicts (two devices cannot have the same IP address).
- Verify that the router interface is up using show interfaces.
- Ensure cables are correctly connected.
- Use debug ip packet to view real-time packet movement.

Key Networking Concepts

1. OSI Model and Layer Functions

Network Layer (Layer 3) is responsible for IP addressing and routing.
Transport Layer (Layer 4) manages data transmission (TCP/UDP).
Data Link Layer (Layer 2) deals with MAC addressing and switching.

2. Common Network Protocols

ICMP: Used by ping to check connectivity.
DHCP: Assigns dynamic IP addresses to network devices.
TCP/IP: The foundational communication protocol of the internet.

Enable Interfaces on the Router:

Enter CLI mode on the router and execute the following commands:

enable
configure terminal
interface FastEthernet 0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
exit
end

Summary and Conclusion

In this lesson, students learned how to configure a basic network using Cisco Packet Tracer. They identified essential devices, configured routers and switches, assigned IP addresses, and tested connectivity. Understanding troubleshooting techniques and networking protocols will help students design and maintain efficient networks.

References

Cisco Networking Academy. (2024). Packet Tracer User Guide.
Tanenbaum, A. S. (2021). Computer Networks (6th ed.). Pearson.
Official Cisco Packet Tracer Tutorials and Labs.