Hands-On Lab 2-1: SOHO Ethernet LAN Design and Implementation

Lab Overview

• Lab Number: 2-1
• • Lab Name: Simple SOHO Ethernet LAN
• • Lab Difficulty: Rated 3/10
• • Approximate Time: 30 minutes
• • Preferred Image: iol-l2 (Switch) and iol-l3 (Router)
• • Lab on: Chapter 2: Fundamentals of Ethernet LANs
• • Figure: 2-1 (Typical Small Ethernet-Only SOHO LAN)

Objective

Design and implement a basic SOHO Ethernet LAN network, connecting multiple devices (PCs and a printer) to a switch and a router for internet access. Understand the critical role of commands like no shutdown in enabling network interfaces and ensuring connectivity.

Scenario Description

This scenario simulates a Small Office/Home Office (SOHO) setup where a router connects the internal network to the internet, and a switch connects local devices. The goal is to configure IP addressing, verify device connectivity, and understand the importance of enabling interfaces without shutdown.

Network Structure

• Subnet: 192.168.1.0/24
• Devices:
  • Router (Default Gateway):
    • Interface e0/3: 192.168.1.1/24
  • Switch: Layer 2 switch for internal device connectivity
  • PCs:
    • PC1: 192.168.1.10/24, Gateway 192.168.1.1
    • PC2: 192.168.1.20/24, Gateway 192.168.1.1
  • Printer:
    • IP: 192.168.1.30/24, Gateway 192.168.1.1

Topology Diagram

Below is the topology diagram for this lab setup:

Prerequisites

1. EVE-NG installed and operational.
2. Images for vios-l2 (Switch) and vios-l3 (Router) are available.
3. Basic understanding of CLI commands for routers and switches.

Implementation Steps

Step 1: Set up the topology

1. Add the following devices in EVE-NG:
   • One Router (iol-l3)
   • One Switch (iol-l2)
   • Two vPCS (PC1 and PC2)
   • One Printer (vPCS or equivalent).
2. Connect:
   • Router e0/3 to Switch port e0/3.
   • PC1 to Switch port e0/0.
   • PC2 to Switch port e0/1.
   • Printer to Switch port e0/2.

Why this step?

Setting up the topology is like laying the groundwork for a building—it ensures that all devices are properly connected and ready for configuration. Without a solid physical setup, the logical configurations won’t work.

Step 2: Configure the Router

1. Access the router and configure its IP address:

enable
configure terminal
interface e0/3
ip address 192.168.1.1 255.255.255.0
no shutdown
exit

Why this step?

This step ensures the router acts as the default gateway for the LAN. Configuring the IP address allows devices to communicate with the router, while the no shutdown command ensures the interface is active and ready to send/receive traffic.

Step 3: Configure PCs and Printer

1. PC1 Configuration:

ip 192.168.1.10 255.255.255.0 192.168.1.1
set pcname PC1

2. PC2 Configuration:

ip 192.168.1.20 255.255.255.0 192.168.1.1
set pcname PC2

3. Printer Configuration:

ip 192.168.1.30 255.255.255.0 192.168.1.1
set pcname Printer

Why this step?

This step assigns IP addresses to each device, ensuring they can communicate within the network. The default gateway configuration allows devices to reach the router for external communication.

Step 4: Verify Basic Connectivity

1. From PC1, ping PC2:

ping 192.168.1.20

• Expected Result: A successful ping indicates that both devices are correctly configured and connected.

2. From PC1, ping the Printer:

ping 192.168.1.30

• Expected Result: The printer should respond, confirming its IP configuration and connectivity.

3. From PC1, ping the Router:

ping 192.168.1.1

• Expected Result: The router should respond, indicating that its interface is active and reachable.

Why this step?

Testing connectivity ensures that all devices are properly configured and can communicate. Pinging devices and the router confirms that IP addressing, physical connections, and gateway settings are correct.

Step 5: Simulate Internet Access (Optional)

1. If the router is configured with NAT or has a simulated external connection, verify access to the external network.
2. Example: Ping a public IP (e.g., 8.8.8.8) if possible.

Why this step?

This optional step simulates real-world internet access, validating the configuration of NAT or external network connectivity.

Verification & Testing

1. Verify Router Interface Status:

show ip interface brief

Tip

If the interface shows administratively down, it means the no shutdown command was not executed. Ensure all interfaces are up before testing connectivity.

2. Ping Devices:

• Ensure all devices can ping each other within the 192.168.1.0/24 subnet.
• Verify that the default gateway (router) responds to ping requests.

3. Test Internet Access (Optional):

• If configured, the router should allow devices to access external networks.

Key Commands

• Assign IP address on PCs/Printer:
  • ip <IP Address> <Subnet Mask> <Gateway>
• Configure router interface:
  • interface <interface>
  • ip address <IP Address> <Subnet Mask>
  • no shutdown
• Test connectivity:
  • ping <Destination IP>

Troubleshooting Tips

• If a device cannot ping another:
  • Verify the IP configuration on both devices.
  • Check switch port status.
  • Ensure the router interface is up and configured correctly.
• Common Issue:
  • Assuming the interface will be active after assigning an IP address. Remember to execute the no shutdown command to bring the interface up.

Key Takeaways

• Learn how to design and implement a simple Ethernet LAN for SOHO environments.
• Understand the role of switches, routers, and default gateways in small networks.
• Learn the importance of commands like no shutdown and their impact on network connectivity.

Real-world Application

This scenario reflects real-world SOHO network setups, often used in small offices or home environments where a single router provides internet access to connected devices.

Common Pitfalls

• Forgetting to configure the default gateway on PCs and printers.
• Using incorrect subnet masks.
• Not enabling the router interface (no shutdown).

Validation Checklist

1. All devices have correct IP configurations.
2. Devices within the subnet can ping each other.
3. The router is reachable from all devices.
4. Internet access is functional if configured.

Lab Notes

• Extra Tip: Always verify interface status with show ip interface brief before testing connectivity. It can quickly help identify inactive interfaces.
• This lab is ideal for beginners to understand the basics of LAN setup and IP configuration.
• Additional steps, such as configuring DHCP on the router, can be added for advanced learners.