Inter Vlan Routing

Router on a stick

Now we will configure inter-vlan routing for which we will use our previous topology.
previous topology - http://www.ittables.com/2013/02/congfiguring-vlans.html
i have added one router into this topology to configure Router on a stick.
router's f0/0 is connected to Switch_1 on f0/20.

Commands to configure router for inter-vlan routing.

Router>enable

Router#configure terminal

Router(config)#interface fastethernet 0/0

Router(config-if)#no shutdown

Router(config-if)#exit

Router(config)#interface fastethernet 0/0.20

Router(config-subif)#encapsulation dot1Q 20

Router(config-subif)#ip address 192.168.20.100 255.255.255.0

Router(config-subif)#exit

Router(config)#interface fastethernet 0/0.30

Router(config-subif)#encapsulation dot1Q 30

Router(config-subif)#ip address 192.168.30.100 255.255.255.0

Router(config-subif)#end

Router#show ip interface brief

Commands to configure Switch_1

Switch_1>enable

Switch_1#configure terminal

Switch_1(config)#interface fastethernet 0/20

Switch_1(config-if)#switchport mode trunk

Switch_1(config-if)#end

Switch_1#

Switch_1#show interfaces trunk

That's all, now you just have to assign default gateway to each computer.
If the computer is in VLAN 20 then default gateway should be 192.168.20.100.
and If the computer is in VLAN 30 then default gateway should be 192.168.30.100.
after this all computers should be able to ping each other.