Protocol Independent Multicast Equal-Cost Multipath (ECMP) Redirect, October 2012
- File formats:
- PROPOSED STANDARD
- Updated by:
- RFC 8736, RFC 9436
- Y. Cai
- pim (rtg)
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A Protocol Independent Multicast (PIM) router uses the Reverse Path Forwarding (RPF) procedure to select an upstream interface and router in order to build forwarding state. When there are equal cost multipaths (ECMPs), existing implementations often use hash algorithms to select a path. Such algorithms do not allow the spread of traffic among the ECMPs according to administrative metrics. This usually leads to inefficient or ineffective use of network resources. This document introduces the ECMP Redirect, a mechanism to improve the RPF procedure over ECMPs. It allows ECMP selection to be based on administratively selected metrics, such as data transmission delays, path preferences, and routing metrics. [STANDARDS-TRACK]
For the definition of Status, see RFC 2026.
For the definition of Stream, see RFC 8729.