6to4 reverse DNS ( test service

Important: 6to4 reverse DNS delegations under are still in a testing phase. This service is not yet adopted, or accepted, by the NRO or the IAB. (10 October 2004).

If you have any operational problems with this website, please contact 6to4@apnic.net. As this service is not currently adopted, the NRO is not able to commit to a specific response time, but will attempt to deal with your query as soon as possible.

About 6to4 reverse DNS

The NRO is currently testing a management interface for the domain in accordance with the methods proposed to the IAB in the Internet draft "6to4 Reverse DNS Delegation" (draft-huston-6to4-reverse-dns-02.txt).

The NRO intends to implement a simple web-based system for rapid deployment of DNS reverse for the reverse-DNS tree, without the normal overheads associated with whois and related registry management.

Connecting to the test service

To use this test service, you must initially connect via your 6to4 gateway, using a 2002::/16 source IPv6 address on SSL secured HTTP (port 443). It is not possible to connect to the service via a web proxy, nor by non-SSL connections.

If you need help with debugging, go to https://6to4.nro.net/. This page will display your source IP address and, if that is within the range 2002::/16, it will show how your source IP address maps into the reverse-DNS space. This may help you determine which specific /48 you are able to delegate from your gateway and also show if an intermediate system is proxying your source address.

Setting up name servers

Before using the forms to delegate your name server (NS), you must first ensure that they are operational. A minimum of two servers must be active and agree about the SOA of the zone. These NSs can be IPv4, IPv6, or dual-stack servers.

Password access

You can access and modify your reverse delegations from any address within the 6to4 gateway you originally used to set up the delegation.

You will also have the option to specify a simple password which will allow you to access this record from outside that original 6to4 gateway

This password is not mandatory when the site is accessed from inside your 6to4 source address. It is intended to prevent an arbitrary access from locking out the domain if the address is not static. (It is recognized that this places far less trust than normal in the correctness of a 6to4 delegation).

Providing a contact email address

You must supply an email address when you set up your delegation. If any changes are made to your delegation record an email will be sent to this aaddress.

Public visibility of new and changed delegations

Updates are made by Dynamic-DNS to the listed NS for and should complete shortly after successful delegation of your 2002::/16 reverse. The exact time taken for the update to become visible can be affected by the time for a DNS NOTIFY protocol event to complete to all listed NS of Typically a change is visible within 10 minutes.

Plain text interface

A simple 'text only' interface is also available for use by 6to4 users who wish to embed their gateway's DNS management into scripted services. This interface responds with plaintext to show status and matches the functionality of the formal web interface. This interface (including full documentation) is available at:


If you have questions about this service in general, or the IAB directions on delegation for this domain, please contact the IAB.