GrouptoRP Mapping Algorithm PIM Working Group draftjoshipimgrouprpmapping00 txt

Group-to-RP Mapping Algorithm PIM Working Group draft-joshi-pim-group-rp-mapping-00. txt Bharat Joshi Infosys Technologies Ltd.

Need for a standard algorithm • No existing RFC/Draft defines a complete algorithm. • A standard algorithm is useful in interoperability. • A standard algorithm can be used to predict the RP for a given Group while running outside a router. This can be used for diagnosing PIM protocol states.

Existing Algorithm • PIM-SM has defined an algorithm which does not: – Consider the origin of a Group-to-RP mapping and therefore treat all of them equally. – Provide the flexibility that a specific statically created Group-to-RP mapping can override any dynamically learned mappings. – Provide the flexibility to give higher priority to a specific PIM mode. • PIM-STD-MIB has defined an algorithm that: – Is not deterministic as it uses implementation-specific values. – Can not be referenced by an implementation.

Proposed Algorithm • Select those Group-to-RP mappings that contains the Group address being looked up. • Select those mappings that are learned using 'static' configuration and are configured with 'override-dynamic' flag. • Perform longest prefix match. • Select mappings based on PIM Mode. PIM-BIDIR is preferred to PIM-SM. • Select mappings based on origin of Group-to-RP mapping. Preference is 'bsr', 'auto-rp', 'embedded', 'static' and 'other'. • Perform the Hash function. • If there are still multiple mappings available, select the one that has higher IP address for RP address.

Next Step • Review in WG mailing list. • Working group item?