Cisco Systems Cisco Systems AT&T Labs This document specifies the extensions to OSPF that enables a router to signal to its neighbor the metric that the neighbor should use towards itself using link-local advertisement between them. The signalling of this reverse metric, to be used on link(s) towards itself, allows a router to influence the amount of traffic flowing towards itself and in certain use-cases enables routers to maintain symmetric metric on both sides of a link between them.