3Com Switch 8800 Advanced Software V5 Configuration Guide

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IPV6 BGP CONFIGURATION
n
■ The term "router" refers to a router in a generic sense or an Ethernet switch
running routing protocols in this document.
■ This chapter describes only configuration specific to IPv6 BGP. For BGP related
information, refer to
“BGP Configuration” on page 419.
When configuring IPv6 BGP, go to these sections for information you are
interested in:
■ “IPv6 BGP Overview” on page 469
■ “Configuration Task List” on page 470
■ “Configuring IPv6 BGP Basic Functions” on page 471
■ “Controlling Route Distribution and Reception” on page 473
■ “Configuring IPv6 BGP Route Attributes” on page 476
■ “Tuning and Optimizing IPv6 BGP Networks” on page 478
■ “Configuring a Large Scale IPv6 BGP Network” on page 480
■ “Displaying and Maintaining IPv6 BGP Configuration” on page 483
■ “IPv6 BGP Configuration Examples” on page 485
■ “Troubleshooting IPv6 BGP Configuration” on page 488
IPv6 BGP Overview BGP-4 manages only IPv4 routing information, thus other network layer protocols
such as IPv6 are not supported.
To support multiple network layer protocols, IETF extended BGP-4 by introducing
IPv6 BGP that is defined in RFC 2858 (Multiprotocol Extensions for BGP-4).
To implement IPv6 support, IPv6 BGP puts IPv6 network layer information into the
attributes of Network Layer Reachable Information (NLRI) and NEXT_HOP.
NLRI attribute of IPv6 BGP involves:
■ MP_REACH_NLRI: Multiprotocol Reachable NLRI, for advertisement of next hop
information of reachable routes.
■ MP_UNREACH_NLRI: Multiprotocol Unreachable NLRI, for withdrawal of
unreachable routes.
The NEXT_HOP attribute of IPv6 BGP is identified by an IPv6 unicast address or
IPv6 local link address.