IETF RFC 4191
Default Router Preferences and More-Specific Routes
|Publication Date:||1 November 2005|
This document describes an optional extension to Router Advertisement messages for communicating default router preferences and morespecific routes from routers to hosts. This improves the ability of hosts to pick an appropriate router, especially when the host is multi-homed and the routers are on different links. The preference values and specific routes advertised to hosts require administrative configuration; they are not automatically derived from routing tables.