VPN Dual-Stack Access

Carriers face a shortage of IPv4 addresses and many carriers have started to deploy IPv6 networks to address this shortage. For widely deployed BGP/MPLS IPv4 VPN services, VPN dual-stack access is a good choice for the transition from IPv4 to IPv6.

VPN interfaces originally only supported a single type of protocol stack. VPN dual-stack allows a VPN to use both IPv4 and IPv6 address families. This allows interfaces bound to a VPN to support both IPv4 VPN and IPv6 VPN.

Figure 1 shows a network diagram of VPN dual-stack access.

Figure 1 Networking diagram of VPN dual-stack access

In Figure 1, IPv4/IPv6 VPN dual-stack access allows VPN sites to support both IPv4 and IPv6 networks. IPv4 and IPv6 services are also transmitted to a PE device through the same interface.