R2511-HP MSR Router Series Layer 3 - IP Routing Configuration Guide(V5)

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• MP_UNREACH_NLRI—Multiprotocol Unreachable NLRI, for carrying prefixes of unfeasible routes
for multiple network layer protocols. Such routes can then be withdrawn.
MP-BGP uses these attributes to advertise feasible and unfeasible routes of different network layer
protocols. BGP speakers not supporting MP-BGP ignore updates containing these attributes and do not
forward them to its peers.
The system supports multiple MP-BGP extensions, including VPN extension (see MPLS Configuration
Guide), IPv6 extension (see "Configuring IPv6 BGP"), and multicast extension (see IP Multicast
Configuration Guide).
Address family
MP-BGP uses address families and subsequent address families to differentiate network layer protocols of
routes contained in the MP_REACH_NLRI and MP_UNREACH_NLRI attributes. For example, an Address
Family Identifier (AFI) of 2 and Subsequent Address Family Identifier (SAFI) of 1 indicates IPv6 unicast
routing information carried in the MP_REACH_NLRI attribute. For address family values, see RFC 1700.
BGP configuration views
BGP uses different views to manage routing information for different address families and different VPN
instances. Most BGP commands are available in all BGP views. BGP supports multiple VPN instances by
establishing a separate routing table for each VPN instance.
This chapter describes only configurations in BGP and BGP-VPN views. For configurations in other views,
see relevant configuration guides.
Table 7 de
scribes different BGP configuration views.
Table 7 BGP configuration views
View names Ways to enter the views Remarks
BGP view
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp]
Configurations in this view apply to
all address families and routes in all
VPN instances (such as
confederation and GR), or apply to
IPv4 unicast routes on the public
network (such as local network
injection, IGP route redistribution,
route summarization, and BGP route
distribution/reception filtering
policies ).
BGP-VPN view
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ipv4-family
vpn-instance vpn1
[Sysname-bgp-ipv4-vpn1]
Configurations in this view apply to
IPv4 unicast routes in the specified
VPN instance.
IPv6 address family view
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ipv6-family
[Sysname-bgp-af-ipv6]
Configurations in this view apply to
IPv6 unicast routes in the public
network.