Redback Networks In this document we first identify the (neighbor-AS based) Group Best Paths for an address prefix as the sufficient subset that can be advertised by a BGP route reflector or a BGP confederation ASBR to eliminate the MED-type route oscillations in a network. We then propose a BGP extension to support the advertisement of the Group Best Paths by a route reflector or a confederation ASBR. The extension also allows the advertisement of all the paths in a group that survive the MED comparison, thus achieving the same routing consistency as the full IBGP mesh. The proposed mechanisms are designed such that the vast majority of the BGP speakers in a network need only minor software changes in order to deploy the mechanisms.