Multiswitch VLAN with Router-on-a-Stick and Trunk Links

Lab Overview

• Lab Title: Comprehensive Real-World VLAN and Inter-VLAN Design
• Level: Advanced
• Estimated Time: ~60 minutes
• Image Used: x86_64_crb_linux_l2-adventerprisek9-ms
• Book Reference: CCNA 200-301 Official Cert Guide Vol.1, Chapter 8

Story Start: “The Network Is Live. And It’s a Mess.”

You’ve just joined the IT team of a growing mid-sized company.

Departments are complaining: “Why are our printers visible to the wrong team?”
Voice calls drop randomly. Management can’t even log in to the switches securely.

You check the setup and it hits you: Everything is in VLAN 1. No segmentation. No security. No voice isolation.

Your task: Redesign the network.

• Create VLANs for departments
• Add trunk links between switches
• Implement Inter-VLAN routing via Router-on-a-Stick

Time to turn chaos into clarity.

Why This Lab Matters

This isn’t a textbook exercise. This is how real companies expect their networks to behave:

• Devices separated by department
• Centralized management access
• Trunked uplinks between floors
• Voice VLANs prioritized for QoS

In this lab, you’ll build all of that. Step by step. By the end, you’ll be able to plan, configure, and troubleshoot an enterprise-grade VLAN design.

What You’ll Build

• 3 switches (SW1, SW2, SW3)
• 4 PCs (PC4, PC5, PC6, PC7) across 2 departments
• VLANs: Data (2 & 3), Management (4)
• Trunk links between SW1 → SW2 and SW1 → SW3
• Router-on-a-Stick Inter-VLAN routing on SW1

VLANs:

• VLAN 2: Data VLAN for PCs in VLAN 2.
• VLAN 3: Data VLAN for PCs in VLAN 3.
• VLAN 4: Management VLAN for network administration.

Subnets:

• VLAN 2: 192.168.2.0/24
• VLAN 3: 192.168.3.0/24
• VLAN 4: 192.168.4.0/24

Trunk Links:

• SW1 to SW2: Trunk carrying VLANs 1, 2, 3, 4 via E0/0.
• SW1 to SW3: Trunk carrying VLANs 1, 2, 3, 4 via E0/1.

Topology Diagram

Below is the topology diagram for this lab setup:

Step-by-Step Implementation

Step 1: Add and Connect Devices in EVE-NG

1. Add 3 switches and 4 vPCS clients in EVE-NG.
2. Connect devices as follows:
   • SW2:
     • PC4 → eth0/1
     • PC5 → eth0/2
   • SW3:
     • PC6 → eth0/1
     • PC7 → eth0/2
3. Create trunk links:
   • SW1 → SW2 (Trunk) → eth0/0, eth0/0.
   • SW1 → SW3 (Trunk) → eth0/1, eth0/0.

Why This Step? You’re laying the physical foundation for a multi-VLAN design. Uplinks between switches must be trunked.

Step 2: Configure Inter-VLAN Routing on Main Switch

• On SW1:

Switch>
Switch>enable
Switch#configure terminal
Switch#hostname SW1

SW1(config)#vlan 2
SW1(config-vlan)#name Data_VLAN_2
SW1(config-vlan)#exit
SW1(config)#vlan 3
SW1(config-vlan)#name Data_VLAN_3
SW1(config-vlan)#exit
SW1(config)#vlan 4
SW1(config-vlan)#name Mgmt_VLAN_4
SW1(config-vlan)#exit

SW1(config)#interface vlan 2
SW1(config-if)#ip address 192.168.2.1 255.255.255.0
SW1(config-if)#exit
SW1(config-if)#interface vlan 3
SW1(config-if)#ip address 192.168.3.1 255.255.255.0
SW1(config-if)#exit
SW1(config-if)#interface vlan 4
SW1(config-if)#ip address 192.168.4.1 255.255.255.0
SW1(config-if)#exit

SW1(config-if)#interface eth0/0
SW1(config-if)#switchport trunk encapsulation dot1q
SW1(config-if)#switchport mode trunk
SW1(config-if)#switchport trunk allowed vlan 1,2,3,4
SW1(config-if)#exit

SW1(config)#interface eth0/1
SW1(config-if)#switchport trunk encapsulation dot1q
SW1(config-if)#switchport mode dynamic auto
SW1(config-if)#switchport trunk allowed vlan 1,2,3,4
SW1(config-if)#end
SW1#