Configure Inter-VLAN routing on a Cisco L3 Catalyst Switch

I recently had to configure inter-VLAN routing at a client's site. I don't have to perform this task on a regular basis, so I figured I would make a post for future reference of a sample implementation.

Ingredients used for the recipe:

• Cisco 2811 Router
• Cisco Catalyst 3560
• Cisco Catalyst 2950

1. Configure the Corp router

Corp> enable
Corp# conf t
Corp# int fa 0/1
Corp(config-if)# description Link_to_L3SW
Corp(config-if)# ip address 172.17.17.9 255.255.255.252
Corp(config-if)# no shut
Corp(config-if)# end

2. Configure the Cisco Catalyst 3560 Switch

L3SW> enable
L3SW# conf t
L3SW(config)# vtp mode server
L3SW(config)# vtp domain test
L3SW(config)# vtp password test
L3SW(config)# vlan 10
L3SW(config-vlan)# name Marketing
L3SW(config-vlan)# end
L3SW(config)# vlan 20
L3SW(config-vlan)# name IT
L3SW(config-vlan)# end
L3SW(config)# int gi 0/1
L3SW(config-if)# switchport trunk encapsulation dot1q
L3SW(config-if)# switchport mode trunk
L3SW(config-if)# switchport nonegotiate
L3SW(config-if)# end
L3SW(config)# ip routing
L3SW(config)# int vlan 1
L3SW(config-if)# ip address 10.100.1.1 255.255.255.0
L3SW(config-if)# no shut
L3SW(config)# int vlan 10
L3SW(config-if)# ip address 10.100.10.1 255.255.255.0
L3SW(config-if)# no shut
L3SW(config)# int vlan 20
L3SW(config-if)# ip address 10.100.20.1 255.255.255.0
L3SW(config-if)# no shut
L3SW(config-if)# end
L3SW(config)# int fa 0/24
L3SW(config-if)# no switchport
L3SW(config-if)# ip address 172.17.17.10 255.255.255.252
L3SW(config-if)# no shut
L3SW(config-if)# end
L3SW(config)# ip route 0 0 172.17.17.9
L3SW(config)# end

3. Configure the Cisco Catalyst 2950 Switch

L2SW> enable 
L2SW# conf t
L2SW(config)# vtp mode client
L2SW(config)# vtp domain test
L2SW(config)# vtp password test
L2SW(config)# int range fa 0/1 - 4
L2SW(config-if-range)# switchport mode access
L2SW(config-if-range)# switchport access vlan 10
L2SW(config-if-range)# int range fa 0/5 - 8
L2SW(config-if-range)# switchport mode access
L2SW(config-if-range)# switchport access vlan 20
L2SW(config-if-range)# end
L2SW(config)# int gi 0/1
L2SW(config-if)# switchport trunk encapsulation dot1q
L2SW(config-if)# switchport mode trunk
L2SW(config-if)# switchport nonegotiate
L2SW(config-if)# end
L2SW(config)# int vlan 1
L2SW(config-if)# ip address 10.100.1.2 255.255.255.0
L2SW(config-if)# no shut
L2SW(config-if)# end
L2SW(config)# ip default-gateway 10.100.1.1
L2SW(config)# end