Switching Concept- Configuring Inter-VLAN Routing (Router on Stick)

Configuring Inter-VLAN Routing- Router on Stick

Today we are going to talk about the configurational part of the Inter-VLAN scenario with the Router on stick which is used earlier in many of the enterprise LAN networks to have the inter-VLAN communication through the Router.

Most of the Routing and Switching experts already knew how to configure the Router on Stick configuration in order to have the inter-VLAN communications. 

Although now a days enterprises uses SVI instead if Router on stick as SVI is the better way to have the communication on the Core Switches. Lets talk about the Scenario now. So in the below mentioned topology, we have two different workstations or you can say users which are in different VLANs named as VLAN 1 and VLAN 2. 

These workstations are connected to the switch named NDNA Switch and further the switch is connected to the router named as NDNA Router.

Inter-VLAN Routing- Router on Stick
Fig 1.1- Inter-vlan Routing 

For an example we are taking the interfaces as Fast Ethernet, but can also take Gig interfaces if required.

We configure the interface Fa0/1 as a trunk port in order to take the traffic of VLAN 1 and VLAN 2. Now lets have a configuration on NDNA Switch and Router as follows

     Configuration on NDNA Switch

   Configuring the IP address for the VLAN

    Now we need to enable trunking on the interface fastEthernet 0/1

    Enabling fast interface with VLAN 2 and enable portfast on the interface.

    FastEthernet 0/3 is already in VLAN1 but enable the port-fast on the interface

After configuring the switch, Lets have a look to configure the Router in order to have the Router on  Stick configuration. 

    Router Configuration

Configure L3 information on the sub-interface 0/0.1 and Now need to enable encapsulation on the sub-interface FastEthernet 0/0.2. 

    Configure L3 information on the sub-interface 0/0.2