•BGP routers establish BGP sessions through the OPEN
message
•OPEN message contains
optional parameters
•BGP session is terminated if OPEN parameters are not recognised
•New parameter: CAPABILITIES
•Multiprotocol extension
•Multiple routes for same destination
•Configures router to negotiate either or both NLRI
•If neighbor configures both or subset, common NRLI is used in both directions
•If there is no match, notification is sent and peering doesn’t come
up
•If neighbor doesn’t include the capability parameters in open, session backs off and reopens with no capability parameters
•Peering comes up in unicast-only mode
•