HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 3 - IP Routing Confi - Page 140
MP-BGP, Overview, MP-BGP extended attributes, Address family, Protocols and standards
View all HP 6125G manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 140 highlights
MP-BGP Overview BGP-4 supports IPv4 unicasts, but does not support other network layer protocols, such as IPv6. To support more network layer protocols, IETF extended BGP-4 by introducing Multiprotocol Extensions for BGP-4 (MP-BGP) in RFC 4760. Routers supporting MP-BGP can communicate with routers not supporting MP-BGP. MP-BGP extended attributes In BGP-4, the attributes for IPv4 address format are NLRI, NEXT_HOP and AGGREGATOR (AGGREGATOR contains the IP address of the speaker generating the summary route). They are all carried in updates. To support multiple network layer protocols, BGP-4 puts information about network layer into NLRI and NEXT_HOP. MP-BGP introduces the following path attributes: • MP_REACH_NLRI-Multiprotocol Reachable NLRI, for advertising feasible routes and next hops • MP_UNREACH_NLRI-Multiprotocol Unreachable NLRI, for withdrawing unfeasible routes These path attributes are both optional non-transitive, so BGP speakers not supporting multiprotocol ignore these attributes and do not forward them to its peers. Address family MP-BGP uses address families to differentiate network layer protocols. For address family values, see RFC 1700, Assigned Numbers. The system supports multiple MP-BGP extensions, including VPN extension, and IPv6 extension (see "Configuring IPv6 BGP."). Different extensions are configured in respective address family view. NOTE: This chapter provides no detailed commands related to any specific extension application in MP-BGP address family view. Protocols and standards • RFC 1771, A Border Gateway Protocol 4 (BGP-4) • RFC 2858, Multiprotocol Extensions for BGP-4 • RFC 3392, Capabilities Advertisement with BGP-4 • RFC 2918, Route Refresh Capability for BGP-4 • RFC 2439, BGP Route Flap Damping • RFC 1997, BGP Communities Attribute • RFC 2796, BGP Route Reflection • RFC 3065, Autonomous System Confederations for BGP • 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 • draft-ietf-idr-restart-08, Graceful Restart Mechanism for BGP 130