5-2. Layer 3 Ethernet Interfaces

  • Layer 3 switching requires an interface on the switch that can forward packets based on Layer 3 addressing.

  • Each Layer 3 interface defines a separate broadcast domain and therefore a separate network.

  • After a Layer 3 interface has been configured with a protocol, it can act as a gateway for other devices in the same broadcast domain.

  • On some switches, you can configure an Ethernet port (interface) as a Layer 3 interface.


A Layer 3 interface is a direct routed interface that is designed to provide Layer 3 processing of packets entering and exiting the interface. Not every physical interface on every switch is designed to be a Layer 3 interface; however, on some switches, each port is, or can be, configured ...

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