6Pe/6Vpe Over L2Tpv3 - Cisco CRS Configuration Manual

Implementing MPLS VPNs over IP Tunnels
Tunnel MA
The Tunnel MA tunnel is used for the tunnel-template configuration and communicating with the BGP. It
supports the /28 IP address by performing these basic tasks:
• Verifies and applies the /28 address pool configuration
• Extends the tunnel information to include the new address pool
• Sends the address pool information to Tunnel EA through the data path control (DPC)
Sending the address pool information to BGP is not mandatory.
Note
Tunnel EA
Tunnel EA sends the address pool information to FIB and also supports the /28 IP address by performing
these basic tasks:
• Processes the address pool information in the DPC from tunnel MA
• Saves the address pool information in the tunnel IDB in EA
• Sends the source address pool information to FIB

6PE/6VPE over L2TPv3

The 6PE/6VPE over L2TPv3 feature supports native IPv6 (6PE) and IPv6 VPN services (6VPE) (described
in RFC 2547) over L2TPv3 tunnels across an IPv4 core network. The 6PE/6VPE over L2TPv3 feature is
supported for label, IPv6 VPN (6VPE) and 6PE traffic.
When an IP VPN service is deployed, VPN traffic is typically transported across the core network between
service provider edge routers (PEs) using MPLS label switched paths (LSPs).
Native IP Layer 3 VPNs (based on generalized RFC 2547) eliminate the need for MPLS between the
participating core routers by implementing L2TPv3 tunnel encapsulation over IP. Such tunnels may be used
to transport VPN traffic between participating edge routers.
The 6VPE over L2TPv3 feature uses IPv6 VRFs, and the multi-protocol BGP advertises VPNv6 service
advertisement framework (SAF) or advertisement framework (AF) between PE routers. The customer edge
IPv6 VPN packets are transported across the provider's IP backbone. Additionally, the customer edge IPv6
VPN packets employ the same encapsulation (L2TPv3 + IPv4 delivery header) as is currently supported in
L2TPv3 for IPv4 VPN services.
The following figure depicts the key elements that are used to extend multi-protocol BGP to distribute VPNv6
prefixes along with the appropriate next hop (IPv4 address) and tunnel attributes. The data encapsulations
remain the same except that the payload is now an IPv6 packet.
Cisco IOS XR Virtual Private Network Configuration Guide for the Cisco CRS Router, Release 6.1.x
6PE/6VPE over L2TPv3
39