Standard group

A peer that is a member of a group uses the configuration parameters that are configured for the group.

Peer group

MSDP speakers that have fully peered MSDP connectivity among themselves form a peer group. Any SA messages received from a peer in a peer group are not forwarded to other peers in the same peer group. Peer groups can be used to reduce SA message flooding, or to simplify peer-RPF flooding (there is no need to run BGP or MBGP among MSDP peers).