Inter-VLAN routing is the process of routing traffic between different VLANs, using either a dedicated router or a multilayer switch. Inter-VLAN routing facilitates communication between devices isolated by VLAN boundaries.
Legacy inter-VLAN routing depended on a physical router port being available for each configured VLAN. This has been replaced by the router-on-a-stick topology that relies on an external router with subinterfaces trunked to a Layer 2 switch. With the router-on-a-stick option, appropriate IP addressing and VLAN information must be configured on each logical subinterface and a trunk encapsulation must be configured to match that of the trunking interface of the switch.
Another option is multilayer inter-vlan option using Layer 3 switching. Layer 3 switching involves SVIs and routed ports. Layer 3 switching is normally configured at the distribution and core layers of the hierarchical design model. Layer 3 switching with SVIs is a form of inter-VLAN routing. A routed port is a physical port that acts similarly to an interface on a router. Unlike an access port, a routed port is not associated with a particular VLAN.
Catalyst 2960 switches can be used in multilayer inter-vlan routing. These switches support static routing, but dynamic routing protocols are not supported. SDM templates are required for enabling IP routing on 2960 switches.
Troubleshooting inter-VLAN routing with a router or a Layer 3 switch are similar. Common errors involve VLAN, trunk, Layer 3 interface, and IP address configurations.