Summary

The configuration of multiple Layer 2 VLANs requires that Layer 3 routing occur between those VLANs. This inter-VLAN routing can be provided external to a Layer 2 switch or within a Multilayer Switch through the configuration of Switch Virtual Interfaces and IP routing. When routing occurs within a Catalyst Multilayer Switch, Cisco Express Forwarding is deployed to facilitate Layer 3 switching through hardware-based tables providing an optimal packet forwarding process.