Bridge domain overview

Bridge domain is an infrastructure that supports the implementation of different switching technologies.

A bridge domain is a generic broadcast domain that is not tied to a specific transport technology. Bridge domains support a wide range of service endpoints including regular L2 endpoints and L2 endpoints over L3 technologies.

Bridge domains switch packets between a range of different endpoint types; for example, attachment circuit (AC) endpoints, Virtual Private LAN Service (VPLS) endpoints, Virtual Leased Line (VLL) endpoints, and tunnel endpoints.

The following are examples of bridge-domain capable services:

VPLS—with multiple AC endpoints and pseudowire (PW) logical interfaces (LIFs)
Local VPLS—with multiple AC endpoints
VLL—with one AC endpoint and one PW endpoint
VLL—with two AC endpoints

A bridge domain that is created for a VPLS application is also referred to as a VPLS instance.