2.4 Inter-VLAN Routing

Inter-VLAN Routing

As we all know, VLANs cannot communicate with other VLANs without the help of a router or a layer 3 switch. Usually, hosts on a VLAN will need to speak to other hosts or devices on other VLANs.

To make this possible we need to configure what’s known as Inter-VLAN Routing. Inter-VLAN Routing uses a layer 3 intermediary device such as a Router or a Layer 3 switch to make these communications possible.

Inter-VLAN routing is the process to forward traffic from one VLAN to another VLAN.


Inter-VLAN Routing options

There is a total of 3 different Inter-VLAN Routing solutions

Legacy Inter-VLAN Routing
A solution that is nowadays considered Legacy and is no longer used since it does not scale well.
Router on a Stick (ROS)
This is a widely used, acceptable solution for a small to medium-sized network
Layer 3 Switching (Using switched Virtual Interfaces [SVIs])
This is by far the best and most scalable solution for medium to large networks.