When SSM source and group filtering is enabled, then for groups in the SSM space, the local router will: - process received PIM (S,G) Join messages only if the {source, group} pair is included in the extended access list corresponding to the list index value configured for this object, and - accept (S,G) local membership requests from the MGMD Router component only if the {source, group} pair is included in the extended access list corresponding to the list index value configured for this object. In other words, the extended access list is a whitelist of the SSM {source, group} pairs for which DC-PIM is permitted to request traffic. rlPimTmEntSsmSrcAndGrpFilter defaults to an empty string, which indicates that no access list is specified.