Configuring Inter-AS IPv6 VPN Option A

In inter-AS IPv6 VPN Option A, an ASBR views the peer ASBR as a CE and uses EBGP+ to advertise IPv6 routes to the peer ASBR.

Usage Scenario

If the MPLS backbone network carrying IPv6 VPN routes spans multiple ASs, the inter-AS VPN solution is required.

If the number of VPNs that access PEs and the number of IPv6 VPN routes are small, inter-AS VPN Option A is recommended. In inter-AS VPN Option A, ASBRs are required to support VPN instances so that they will be capable of managing IPv6 VPN routes. In addition, ASBRs need provide dedicated interfaces for inter-AS IPv6 VPNs, which can be sub-interfaces or physical interfaces. Therefore, the requirement for ASBRs' performance is rather high, but no inter-AS configurations need to be performed on ASBRs.

Pre-configuration Tasks

Before configuring inter-AS VPN Option A, complete the following tasks:

Configure an IGP for the MPLS backbone network in each AS for IP connectivity of the backbone network in each AS.
Enable MPLS on the PEs and ASBRs.
Establish tunnels (LSPs, MPLS TE tunnels, or SR-MPLS TE tunnels) between PEs and ASBRs in the same AS.
Enable IPv6 on interfaces to be configured with IPv6 addresses.

Procedure

Configure a basic BGP/MPLS IPv6 VPN for each AS. For details, see Configuring a Basic BGP/MPLS IPv6 VPN.
Configure ASBRs in different ASs to view each other as a CE.
Configure an IPv6-address-family-supporting VPN instance on each PE and ASBR. For configuration details, see Configuring a VPN Instance.
After the configurations are complete, the PEs can access their attached CEs, and ASBRs in different ASs can access each other.

In inter-AS VPN Option A, on the same IPv6 VPN, the VPN targets of the IPv6-address-family-supporting VPN instances of the ASBR and PE that are in the same AS must match. This is not required for the PEs in different ASs.

Checking the Configurations

After completing the configurations, run the following commands to check the configurations:

Run the display bgp vpnv6 all peer command on the PE or ASBR to check information about BGP peer relationships.

Run the display bgp vpnv6 all routing-table command on the PE or ASBR to check VPNv6 routing information.

Run the display ipv6 routing-table vpn-instance [ vpn-instance-name ] command on the PE or ASBR to check the routing table of the VPN instance IPv6 address family.