China Mobile Huawei Arrcus, Inc. Individual Juniper Juniper Bit Index Explicit Replication (BIER) is a new multicast forwarding architecture that doesn't require an explicit tree-building protocol and doesn't require intermediate routers to maintain per-tree multicast states. Some BIER-specific information and state, which are only in proportion to the network but not per-tree, do need to be advertised, calculated, and maintained. This document describes BGP extensions for advertising the BIER information and methods for calculating BIER states based on the advertisement in a single Administrative Domain.