BGP Signaling for VPLS PE Routers Overview
BGP can autonomously signal pseudowires between the PE routers participating in the same virtual private LAN service (VPLS) network. As PE routers are added to and removed from the VPLS network, BGP can signal pseudowires to new PE routers and tear down old pseudowires to old PE routers. Each PE router only needs to be configured with the identity of the VPLS routing instance. Each PE router does not need to be configured with the identities of all of the PE routers that are or might become a part of the VPLS network.
In the VPLS documentation, the word router in terms such as PE router is used to refer to any device that provides routing functions.
When you configure BGP for signaling in a VPLS network, customer sites can be either single-homed to a single PE router or multihomed to two or more PE routers. Multihoming provides redundancy for the connection between the customer site and the service provider’s network.
You can either configure all of the PE routers in the VPLS network as a full mesh or you can use BGP route reflectors. For full mesh configurations, each PE router needs to be able to create a bidirectional pseudowire to each of the other PE routers participating in the VPLS network.