# Configuring Access Node Control Protocol for IGMP

By using ANCP, IGMP is no longer terminated or proxied at the access node. Instead, IGMP passes through the access node transparently. B-RAS terminates both the data PVC and IGMP. After possible user permission verification, B-RAS may instruct the access node, by using GSMP, to establish a multicast branch for the subscriber port.

Access Node Control Protocol (ANCP), also known as Layer 2 Control (L2C) works with a special IGMP session to collect OIF mapping events in a scalable manner. For additional information about configuring ANCP for IGMP, see Configuring ANCP in the JunosE IP Services Configuration Guide.

For additional information about OIF mapping, see Configuring Group Outgoing Interface Mapping .