H3C Technologies H3C S10500 Series Switches - Manual (Page 251)

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MBGP configuration
NOTE:
The term router in this document refers to both routers and Layer 3 switches.
MBGP overview
BGP-4 can carry routing information for IPv4 only. IETF defined Multiprotocol Border Gateway Protocol
(MP-BGP) to extend BGP-4 so that BGP can carry routing information for multiple network-layer protocols.
For a network, the topology for multicast might be different from that for unicast. To distinguish them, the
MP-BGP enables BGP to carry the unicast Network Layer Reachability Information (NLRI) and multicast
NLRI separately. The multicast NLRI performs reverse path forwarding (RPF) exclusively. In this way, route
selection for a destination through the unicast routing table and through the multicast routing table have
different results, ensuring consistent unicast forwarding and normal multicast between domains.
MP-BGP is defined in RFC 2858 (Multiprotocol Extensions for BGP-4). The application of MP-BGP on
multicast is called Multicast BGP (MBGP).
NOTE:
•
This document covers configuration tasks related to multiprotocol BGP for IP multicast only. For more
information about BGP, see
Layer 3—IP Routing Configuration Guide.
• For more information about RPF, see the chapter “Multicast routing and forwarding configuration.”
Protocols and standards
• RFC 2858, Multiprotocol Extensions for BGP-4
• RFC 3392, Capabilities Advertisement with BGP-4
• draft-ietf-idmr-bgp-mcast-attr-00, BGP Attributes for Multicast Tree Construction
• RFC 4271, A Border Gateway Protocol 4 (BGP-4)
• RFC 5291, Outbound Route Filtering Capability for BGP-4
• RFC 5292, Address-Prefix-Based Outbound Route Filter for BGP-4
MBGP configuration task list
Complete the following tasks to configure MBGP:
Task Remarks
Configuring MBGP basic functions Required
Configuring MBGP route redistribution Required
Configure default route redistribution into MBGP Optional
Controlling route
advertisement and
reception
Configuring MBGP route summarization Optional