# BGP Signaling for VPLS Overview

BGP multiprotocol extensions (MP-BGP) enable BGP to support IPv4 services such as BGP/MPLS VPNs, which are sometimes known as RFC 2547bis VPNs. VPLS with BGP signaling is actually a BGP-MPLS application that has much in common with BGP/MPLS VPNs.

The procedures for configuring BGP signaling for BGP/MPLS VPNs and for VPLS are similar except, for VPLS, you must configure both of the following BGP address families:

- L2VPN—The L2VPN address family enables you to configure the PE router for VPLS (or VPWS) L2VPNs to exchange layer 2 network layer reachability information (NLRI) for all VPLS (or VPWS) instances. Optionally, you can use the signaling keyword with the address-family command for the L2VPN address family to specify BGP signaling of VPLS reachability information. Currently, you can omit the signaling keyword with no adverse effects.
- VPLS—The VPLS address family enables you to configure the PE router to exchange layer 2 NLRI for a specified VPLS instance.

BGP can exchange information in a VPLS topology within these address families. Specifically, BGP builds a full mesh of label-switched paths (LSPs) among all of the VPLS instances on each of the PE routers participating in a particular VPLS domain.

#### Related Documentation

- Configuring BGP Signaling for VPLS
- Configuring BGP Routing
- Configuring BGP-MPLS Applications