BGP Extensions for Bit Index Explicit Replication
RFC 9793, “BGP Extensions for Bit Index Explicit Replication”, is a Proposed Standard document published in June 2025 by X. Xu, M. Chen, K. Patel, IJ. Wijnands, T. Przygienda, Z. Zhang. The canonical text is published by the RFC Editor.
Abstract
Bit Index Explicit Replication (BIER) is a 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 states, which are only in proportion to the number of BIER routers 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 advertisements.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 9793 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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