NAT64 usage and configuration

For IPv6 only customers without IPv4 connectivity, we provide DNS64 resolvers and NAT64 routers to provide IPv4 connectivity.

Please note, applications must be IPv6 aware. Any application or software which defaults to or has hardcoded IPv4 addresses, will not work through NAT64.

DNS64 resolvers

We have a pair of recursive DNS resolvers listening on IPv6 addresses that provide DNS64 address mappings for IPv4:

  • 2a00:1098:0:80:1000:3b:0:1
  • 2a00:1098:0:82:1000:3b:0:1

We also have separate DNS64 and NAT64 servers in Fremont, to minimise latency for users of our US network. For servers in Fremont, please configure the following DNS64 resolvers instead:

  • 2a06:1c80:3::2:1
  • 2a06:1c80:3::3:1

You will need to configure your server to use one or all of the above addresses. Once configured, you do not need to do anything further. Our NAT64 routers will handle the rest for you.

NAT64 prefix

If you are running your own DNS resolver, you can still use our NAT64 routers. You will need to configure your DNS resolver to do DNS64 using the well-known prefix:


For Bind9 users, this can be done using the following example:

dns64 64:ff9b::/96 {
  clients { ::1;; };

IPv4 addresses

When using our NAT64 service, your connections will be NATed out of one of a number of IPv4 addresses. Please note that the IPv4 address used may change during network maintenance, and we may add new IPs to the list below in future. If you would like to be notified when we add new IP addresses, please contact support.

Current NAT64 IPv4 addresses: