Beyond IPv6 basics: NAT64, DNS64 and anycast

The idea

A laptop with only IPv6 reaches legacyServer, which has only IPv4, through officeRouter, a Router, with DNS64 and NAT64. Then eastServer and westServer hold one anycast address, and the laptop and branchLaptop each reach the nearer one.

Steps

1. An IPv6-only laptop, an IPv4-only server

   Many new networks run IPv6 only, while many servers still have only IPv4. The laptop has only IPv6, legacyServer only IPv4: list both, then ping legacyServer from the laptop.

   laptop:~# ip -br addr show dev eth0
   legacyServer:~# ip -br addr show dev eth0
   laptop:~# ping -c 1 -W 1 10.0.2.11

2. DNS64: an AAAA record made up from an A record

   To connect, the laptop needs an IPv6 address for legacy.lab, which has none: legacy.lab has only an A record, 10.0.2.11, and no AAAA. Ask the laptop's Recursive resolver for both, then legacy.lab's own name server for the AAAA.

   laptop:~# dig +short A legacy.lab
   laptop:~# dig +short AAAA legacy.lab
   resolver:~# dig AAAA legacy.lab @10.0.2.10