BGP Prefix Independent Convergence

The information below is for an old version of the document
Document Type Expired Internet-Draft (rtgwg WG)
Authors Ahmed Bashandy  , Clarence Filsfils  , Prodosh Mohapatra 
Last updated 2021-02-13 (latest revision 2020-08-12)
Replaces draft-bashandy-rtgwg-bgp-pic
Stream Internet Engineering Task Force (IETF)
Expired & archived
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Stream WG state In WG Last Call
Document shepherd Yingzhen Qu
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


In the network comprising thousands of iBGP peers exchanging millions of routes, many routes are reachable via more than one next-hop. Given the large scaling targets, it is desirable to restore traffic after failure in a time period that does not depend on the number of BGP prefixes. In this document we proposed an architecture by which traffic can be re-routed to ECMP or pre-calculated backup paths in a timeframe that does not depend on the number of BGP prefixes. The objective is achieved through organizing the forwarding data structures in a hierarchical manner and sharing forwarding elements among the maximum possible number of routes. The proposed technique achieves prefix independent convergence while ensuring incremental deployment, complete automation, and zero management and provisioning effort. It is noteworthy to mention that the benefits of BGP-PIC are hinged on the existence of more than one path whether as ECMP or primary-backup.


Ahmed Bashandy (
Clarence Filsfils (
Prodosh Mohapatra (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)