In inter-AS BGP AD VPLS Option C, only PEs in different ASs on the ISP network need to establish public network tunnels. ASBRs do not need to maintain inter-AS L2VPN information or reserve interfaces for inter-AS L2VPN PWs. As L2VPN information is exchanged only between PEs, this solution requires few resources and is easy to deploy.
Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run peer ipv4-address label-route-capability
The capability to exchange labeled IPv4 routes with the local ASBR is configured.
The configuration is committed.
Run system-view
The system view is displayed.
Run interface interface-type interface-number
The view of the interface that connects to the peer ASBR is displayed.
Run ip address ip-address { mask | mask-length }
An IP address is configured for the interface.
Run mpls
MPLS is enabled.
Run quit
Return to the system view.
Run bgp as-number
The BGP view is displayed.
Run peer ipv4-address label-route-capability
The capability to exchange labeled IPv4 routes with the local PE is configured.
In inter-AS Option C, an inter-AS LSP must be established, and the public network routes advertised between PEs and ASBRs carry MPLS labels.
An EBGP peer relationship must be established between ASBRs in different ASs for them to exchange labeled IPv4 routes.
The public network routes carrying MPLS labels are advertised through MP-BGP. According to relevant standards, label mappings about routes can be piggybacked inside the BGP Update messages that are used to advertise these routes. This feature is implemented through an extended BGP attribute, which enables BGP peers to process labeled IPv4 routes.
Run peer ipv4-address as-number as-number
The peer ASBR is configured as an EBGP peer.
Run peer ipv4-address label-route-capability [ check-tunnel-reachable ]
The capability to exchange labeled IPv4 routes with the peer ASBR is configured.
The configuration is committed.
ASBRs allocate MPLS labels to IPv4 routes based on the configured routing policies.
Perform the following steps on each ASBR:
Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run network ip-address [ mask | mask-length ] [ route-policy route-policy-name ]
The capability to advertise the local PE's loopback interface address used for BGP sessions to the peer ASBR is configured.
The configuration is committed.
Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run peer ipv4-address as-number as-number
The peer PE is specified as an EBGP peer.
Run peer ipv4-address ebgp-max-hop [ hop-count ]
The maximum number of hops allowed for an EBGP peer session is specified.
When establishing an EBGP peer relationship between two indirectly connected PEs in different ASs, specify the maximum number of hops allowed for the EBGP peer session and ensure that the two PEs are reachable to each other.
Run l2vpn-ad-family
The L2VPN AD address family view is displayed.
Run peer ipv4-address enable
The capability to exchange routes with BGP peers is configured.
After you specify a peer in the BGP-L2VPN-AD address family view, the BGP AD signaling capability is enabled by default.
Run signaling vpls or peer ip-address signaling vpls
The VPLS signaling capability is enabled.
(Optional) Run signaling vpls-ad disable
The BGP AD signaling capability is disabled.
The BGP AD signaling capability is automatically enabled after you run the peer enable command in the L2VPN-AD address family view. When configuring BGP VPLS, you can disable the BGP AD signaling capability.
(Optional) Run peer ipv4-address next-hop-invariable
The PE is configured to advertise labeled IPv4 routes to EBGP peers without changing the next hops of these routes.
This step is used in scenarios where an RR is used to advertise the L2VPN label blocks. The next hop cannot be changed when label blocks are advertised between RRs. For other scenarios, skip this step.
The configuration is committed.