Chapter 6. InterVLAN Routing
VLANs divide the network into smaller broadcast domains but also block communication between domains. A Layer 3 device, such as a router or multilayer switch, enables communication between users in different VLANs or subnets.
InterVLAN Routing Using an External Router
A Layer 2 switch connects to a router to provide reachability between VLANs. This is accomplished either via separate physical links for each VLAN or a trunk link from the switch to the router. A trunk link is most common, and this type of setup is frequently called router on a stick. When using a trunk link you must create separate subinterfaces on the router’s physical interface—one subinterface for each VLAN plus one for the native VLAN. The router ...