Configuring MP-EBGP for PEs and ASBRs in Different ASs

By introducing extended community attributes into BGP, MP-EBGP can advertise VPNv4 routes between PEs. After an MP-EBGP peer relationship is established between ASBRs in Different ASs, an ASBR can advertise the VPNv4 routes of its AS to the other ASBR.

Procedure

Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run peer peer-address as-number as-number
The peer ASBR is specified as an EBGP peer.
Run peer peer-address connect-interface loopback interface-number
The loopback interface is specified as the outbound interface of BGP sessions.
Run peer ipv4-address ebgp-max-hop [ hop-count ]
The maximum number of hops between PEs for which an EBGP peer relationship is to be configured is specified. PEs of different ASs are generally not directly connected. To set up the EBGP peer relationship between PEs of different ASs, configure the maximum number of hops between PEs and ensure that PEs are reachable.
Run ipv4-family unicast
The unicast IPv4 address family view is displayed.
Run peer peer-address enable
The capability to exchange IPv4 routes is enabled.
(On PEs) Run quit
The BGP view is displayed.
(On PEs) Run ipv4-family vpnv4 [ unicast ]
The BGP-VPNv4 address family view is displayed.
(On PEs) Run peer peer-address enable
The capability to exchange VPNv4 routes is enabled.
Run commit
The configuration is committed.