RFC 4760:Multiprotocol Extensions for BGP-4
RFC-Ref

router


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... route to a peer (b) to permit a router to advertise the Network Layer address ...
... Layer address of the router that should be used as the next hop to the destinations ...
... Network Address of the next router on the path to the destination system. The Network Layer protocol ...
... Network Layer address of the router that SHOULD be used as the next hop to the destinations ...



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