H3C Technologies H3C S7500E Series Switches - Manual (Page 235)

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8
MBGP Configuration
The term “router” refers to a router or a Layer 3 switch in this document.
When configuring MBGP, go to these sections for information you are interested in:
z MBGP Overview
z Protocols and Standards
z MBGP Configuration Task List
z Configuring MBGP Basic Functions
z Controlling Route Advertisement and Reception
z Configuring MBGP Route Attributes
z Tuning and Optimizing MBGP Networks
z Configuring a Large Scale MBGP Network
z Displaying and Maintaining MBGP
z MBGP Configuration Example
MBGP Overview
BGP-4 is capable of carrying routing information for IPv4 only. IETF defined multiprotocol BGP
extensions to carry routing information for multiple network layer protocols.
For a network, the multicast topology may be different from the unicast topology. To meet the
requirement, the multiprotocol BGP extensions enable BGP to carry the unicast Network Layer
Reachability Information (NLRI) and multicast NLRI separately, and the multicast NLRI is used to
perform reverse path forwarding (RPF) exclusively. In this way, route selection for a destination
through the unicast routing table and through the multicast routing table will have different results,
ensuring normal unicast and multicast routing.
Multi-protocol BGP is defined in RFC 2858 (Multiprotocol Extensions for BGP-4).
Multi-protocol BGP for IP multicast is referred to as Multicast BGP (MBGP) for short.