Configuring MP-EBGP Between ASBRs in Different ASs

Context

In inter-AS VPN Option B, you need not create VPN instances on ASBRs. The ASBR does not filter the VPNv4 routes received from the PE in the same AS based on VPN targets. Instead, it advertises the received VPNv4 routes to the peer ASBR through MP-EBGP.

In the switch, an ASBR can only change the next-hop address of a VPNv4 route to the ASBR's address before advertising the route to a PE.

Perform the following steps on the ASBR.

Procedure

Run system-view
The system view is displayed.
Run interface interface-type interface-number
The view of the interface connected with the ASBR interface is displayed.
Run ip address ip-address { mask | mask-length }
The interface IP address is configured.
Run mpls
The MPLS capability is enabled.
Run quit
Return to the system view.
Run bgp { as-number-plain | as-number-dot }
The BGP view is displayed.
Run peer ipv4-address as-number as-number
The peer ASBR is specified as the EBGP peer.
(Optional) Run peer { ipv4-address | group-name } ebgp-max-hop [ hop-count ]
The maximum number of hops is configured for the EBGP connection.

Generally, one or multiple directly connected physical links exist between EBGP peers. If the directly connected physical link(s) are not available, run this command to ensure that the TCP connection can be set up between the EBGP peers through multiple hops.
Run ipv4-family vpnv4 [ unicast ]
The BGP-VPNv4 address family is displayed.
Run peer ipv4-address enable
The exchange of IPv4 VPN routes with the peer ASBR is enabled.