# Configuring IPv6 Tunneling over IPv4 MPLS

To configure IPv6 tunneling over MPLS:

1. On PE 1, configure both an IPv4 and an IPv6 interface toward the CE router. Use an IPv4-compatible IPv6 address.
   host1(config)#interface atm2/0.1 host1(config)#atm pvc 1 0 1 aal5snap host1(config)#ip address 11.19.1.1 255.255.255.0 host1(config)#ipv6 address ::11.19.1.1/126
2. On PE 1, configure an IPv4 interface facing the core.

   | Note: For forwarding to work, you must configure at least one IPv6 interface on each line module where MPLS-encapsulated IPv6 traffic is expected. You can easily accomplish this by also configuring an IPv6 address on the core-facing interface.

   host1(config)#interface atm3/0.1 host1(config)#atm pvc 30 0 30 aal5snap host1(config)#ip address 10.10.10.1 255.255.255.0 host1(config)#ip address ::10.10.10.1/120
3. On PE 1, configure a loopback interface.
   host1(config)#interface loopback 1 host1(config)#ip address 1.1.1.1 255.255.255.0
4. On PE 1, configure an IPv4 IGP and an MPLS signaling protocol in the core.
5. On PE 1, set up a base tunnel, or verify that one exists between the loopback addresses on the PE routers.
6. On PE 1, configure MP-BGP.
   1. Enable BGP.
      host1(config)#router bgp 100
   2. Configure the MP-BGP CE and PE neighbors.
      host1(config-router)#neighbor 11.19.1.2 remote-as 65000 host1(config-router)#neighbor 2.2.2.2 remote-as 100
   3. Activate the neighbors in the IPv6 address-family.
      host1(config-router)#address-family ipv6 unicast host1(config-router-af)#neighbor 11.19.1.2 activate host1(config-router-af)#neighbor 2.2.2.2 activate
   4. Configure the MP-BGP PE neighbor to send labeled IPv6 prefixes.
      host1(config-router-af)#neighbor 2.2.2.2 send-label host1(config-router-af)#neighbor 2.2.2.2 update-source loopback 1 host1(config-router-af)#neighbor 2.2.2.2 next-hop-self host1(config-router-af)#exit-address-family
7. Configure the P router with an IPv4 IGP and an MPLS signaling protocol.
8. Configure the PE 2 router as you did PE 1 in Steps 1–6.
9. Configure the CE 1 and CE 2 routers.
   1. Configure both an IPv4 and an IPv6 interface toward the PE router. Use an IPv4-compatible IPv6 address.
   2. Configure an MP-BGP session to the PE router over TCPv4, and activate the IPv6 unicast address family.

#### Related Documentation

- neighbor send-label
- Carrier-of-Carriers IPv6 VPNs Overview