BGP MULTI_EXIT_DISC (MED) Considerations

The BGP MULTI_EXIT_DISC (MED) attribute provides a mechanism for BGP speakers to convey to an adjacent AS the optimal entry point into the local AS. While BGP MEDs function correctly in many scenarios, a number of issues may arise when utilizing MEDs in dynamic or complex topologies. This document discusses implementation and deployment considerations regarding BGP MEDs and provides information with which implementers and network operators should be familiar. This memo provides information for the Internet community.