This chapter contains examples of configuring subinterfaces.

A single physical interface when required to handle multiple VLAN traffic, can be divided into multiple logical interfaces called sub-interfaces.

All sub-interfaces under a physical port will use their parent port for transmitting and receiving data.

Sub-interfaces can be used for various purposes, as for inter-vlan routing to happen when router has only one physical interface, two sub-interfaces each with different IP network can be created under it and data can be routed between them.

Sub-interfaces let you divide a physical interface into multiple logical interfaces that are tagged with different VLAN identifiers. Because VLANs allow you to keep traffic separate on a given physical interface, you can increase the number of interfaces available to your network without adding additional physical interfaces.