NAT64 usage and configuration

For IPv6 only customers without IPv4 connectivity, we currently provide two 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.


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

Important note

Users who currently utilize their own DNS server locally, should refer to the examples section for details about DNS64 configuration.

Linux, BSD based servers


OS X based servers

System Preferences > Network > Advanced > DNS

Fremont Servers

We 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:



Where applicable, users running a DNS server locally should configure DNS64 support to use any of the following ranges.

Or for servers in Fremont:

For Bind9 users, this can be done using the following examples

dns64 2a00:1098:0:80:1000:3a::/96 {
  clients { ::1;; };