A Private IPv4 User Traversing the IPv6 Network to Access an IPv4 Internet Server

The DS-Lite NAT policy translates source addresses in the private IPv4 packet headers, allowing private IPv6 users to access the Internet using public IP addresses.

As shown in Figure 1, in the middle and later phases of the evolution from IPv4 to IPv6, the carrier's MAN has all been upgraded to the IPv6 network, but some IPv4 users still exist. In this case, the DS-Lite NAT can ensure normal operation of all services.

Figure 1 DS-Lite NAT networking diagram

1. Establish an IPv4 over IPv6 tunnel between the CPE and CGN (DS-lite tunnel on the CGN), allowing private IPv4 users to traverse the IPv6 network to access the CGN.
2. Deploy the DS-Lite NAT policy on the CGN to translate source addresses in packets sent from a private network to the Internet into public addresses, allowing private network users to access the Internet.