Author: Jean-Gabriel Dick <jean-gabriel.dick@curie.fr>
Bug 1843: multicast-siblings cache_peer option for optimising multicast ICP relations
'multicast-siblings' : this option is meant to be used only for cache peers of
type "multicast". It instructs Squid that ALL members of this multicast group
have "sibling" relationship with it, not "parent". This is an optimization
that avoids useless multicast queries to a multicast group when the requested
object would be fetched only from a "parent" cache, anyway. It's useful, e.g.,
when configuring a pool of redundant Squid proxies, being members of the same
multicast group.