Cisco Packet Tracer Lab: VLAN and Inter-VLAN Routing

Overview

This lab demonstrates the configuration of VLANs, trunking between switches, and inter-VLAN routing using the router on a stick method in a network consisting of multiple PCs, switches, and a router. The goal is to achieve connectivity between different VLANs and ensure proper network segmentation.

Objectives

1. Configure Switch Interfaces:

   • Configure the switch interfaces connected to the PCs as access ports in their respective VLANs.

2. Trunk Configuration:

   • Configure the connection between SW1 and SW2 as a trunk link.
   • Only allow necessary VLANs on the trunk link.
   • Configure an unused VLAN as the native VLAN.
   • Ensure that all necessary VLANs exist on both switches.

3. Router on a Stick:

   • Configure the connection between SW2 and R1 using the router-on-a-stick method.
   • Assign the last usable address of each subnet to R1's subinterfaces.

4. Connectivity Testing:

   • Ensure all PCs can ping each other to verify proper configuration and connectivity.

Network Diagram

VLAN Configuration

Switch 1 (SW1)

• PC1 & PC2: VLAN 10
• PC3 & PC4: VLAN 30

Switch 2 (SW2)

• PC5: VLAN 20
• PC6 & PC7: VLAN 10

Configuration Steps

1. Configure Access Ports on Switches

On SW1, configure the interfaces connected to PCs as access ports in the correct VLANs:

SW1(config)# interface range fa0/1 - 2
SW1(config-if-range)# switchport mode access
SW1(config-if-range)# switchport access vlan 10

SW1(config)# interface range fa0/3 - 4
SW1(config-if-range)# switchport mode access
SW1(config-if-range)# switchport access vlan 30

On SW2, configure the access ports:

SW2(config)# interface range fa0/1
SW2(config-if)# switchport mode access
SW2(config-if)# switchport access vlan 20

SW2(config)# interface range fa0/2 - 3
SW2(config-if-range)# switchport mode access
SW2(config-if-range)# switchport access vlan 10

2. Configure Trunk Link Between SW1 and SW2

To allow communication between VLANs on both switches, configure the link between SW1 and SW2 as a trunk:

SW1(config)# interface gi0/1
SW1(config-if)# switchport mode trunk
SW1(config-if)# switchport trunk allowed vlan 10,30
SW1(config-if)# switchport trunk native vlan 1001

On SW2, configure the other side of the trunk link:

SW2(config)# interface gi0/1
SW2(config-if)# switchport mode trunk
SW2(config-if)# switchport trunk allowed vlan 10,30
SW2(config-if)# switchport trunk native vlan 1001

3. Create VLAN 30 on SW2 and Configure Interface g0/2

SW2(config)# vlan 30
SW2(config)# interface gi0/2
SW2(config-if)# switchport mode trunk
SW2(config-if)# switchport trunk allowed vlan 10,20,30

4. Configure Router on a Stick (R1)

On R1, configure subinterfaces for each VLAN, assigning the last usable IP address from each subnet to the subinterfaces:

R1(config)# interface g0/0.10
R1(config-subif)# encapsulation dot1Q 10
R1(config-subif)# ip address 10.0.0.62 255.255.255.192

R1(config)# interface g0/0.20
R1(config-subif)# encapsulation dot1Q 20
R1(config-subif)# ip address 10.0.0.126 255.255.255.192

R1(config)# interface g0/0.30
R1(config-subif)# encapsulation dot1Q 30
R1(config-subif)# ip address 10.0.0.190 255.255.255.192

5. Verify Connectivity

After completing the configuration, verify connectivity by pinging between PCs in different VLANs. All PCs should be able to reach each other:

PC1> ping 10.0.0.129  # Ping PC3 from PC1
PC2> ping 10.0.0.65   # Ping PC5 from PC2

If the pings are successful, the lab is complete, and inter-VLAN routing is functioning properly.

Conclusion

In this lab, I successfully configured VLANs on two switches, established a trunk link between them, and set up inter-VLAN routing using the router on a stick method. By configuring the router's subinterfaces and assigning the appropriate IP addresses, I ensured that devices in different VLANs could communicate seamlessly. After verifying connectivity through successful pings between PCs in different VLANs, I confirmed that the network is functioning as expected. This lab helped me gain a deeper understanding of VLAN segmentation, trunking, and inter-VLAN routing, which are crucial components of network design and management.

Acknowledgements

Special thanks to Jeremy's IT Lab for providing valuable resources and tutorials that greatly contributed to the completion of this exercise. His in-depth explanations and practical demonstrations have been instrumental in enhancing my understanding of Cisco networking concepts and the effective use of Packet Tracer.

For more information and additional resources, visit Jeremy's IT Lab and check out his YouTube for the full course, Jeremy's IT Lab Free CCNA 200-301 | Complete Course