Aug 062010


As part of Dyn Inc.’s IPv6 implementation plan, has recently made a new IPv6 nameserver available for Custom DNS and Secondary DNS customers. Whether you’re looking to get a jump on the transition to IPv6 or you’re simply curious, we’ve created this short tutorial to help you make use of the new nameserver.


Before we begin, please note that the information in this article is purely for testing and educational purposes. does not currently guarantee the availability of its IPv6 test servers, so please exercise caution when adding them to the delegation of a domain. Additionally, this article does not provide instructions for configuring IPv6 in your environment, and assumes that you have already done so.

Adding IPv6 Nameservers For Your Domain

1. Enable the Expert Interface in Custom DNS (Secondary DNS customers may skip to Step 2)

  • Under Zone Level Services, select the Custom DNS zone for which you wish to enable IPv6.
  • In the upper-right corner of the zone page, you will see a button labeled Preferences. Please click this to view your zone’s settings.
  • On the Preferences page, you will see a button labeled Enable Expert Interface in the lower-right hand corner. Please click this to change your interface type from Standard to Expert (you can change this back at any time).
  • You should be returned to the configuration page for your Custom DNS service. Your records will be displayed somewhat differently, in a format closer to the layout of records in BIND.

2. Create an NS Record for

  • In Custom DNS, under the Add DNS Record section, leave the host field blank; enter 43200 under TTL; select the record type of NS; and enter in the Data field. Click Create Record, and move to Step 3.
  • For Secondary DNS, in your domain’s zone file on your master server, add:
@		IN		NS
  • In named.conf, you will need to add the nameserver’s IPv6 address to the allow-transfer statement:
allow-transfer {
  • Finally, increment your zone serial so the secondary servers will retrieve the latest copy of your zone file.

3. Delegate to

  • If your domain is registered with, visit your domain’s registration page and click the change link under Nameservers. (If your domain is registered elsewhere, you may need to contact your registrar for this step.)
  • Select Enter Nameservers Manually Below to display the list of your current nameservers.
  • Click the Add another nameserver link to provide an additional field, and add to the list.Click Save Nameservers to complete the change.

Trying It Out

Now that the IPv6 test server has been added to your domain’s delegation, you can see the results with a simple dig query. Here is a sample output using our domain, which uses Secondary DNS:

As you can see from the “Received [xyz] bytes from [IPv6 address]” lines from our dig +trace, each leg of the journey requested and received a response using IPv6:

;; Received 512 bytes from ::1#53(::1) in 0 ms
;; Received 492 bytes from 2001:500:2f::f#53(F.ROOT-SERVERS.NET) in 58 ms
;; Received 205 bytes from 2001:503:231d::2:30#53(B.GTLD-SERVERS.NET) in 54 ms
;; Received 221 bytes from 2607:f590:f2::2#53( in 0 ms

The use of the -6 flag on our dig query forced it to use only IPv6 transit to perform the query. The results above are actually fairly lucky, since not all of the possible servers we could have asked have IPv6 addresses; if you use the -6 flag and see a failure (such as couldn’t get address for ‘’: not found), it means dig chose to query a server which lacks an IPv6 address and gave up.

To demonstrate dual-stack functionality, let’s try the query again, this time without forcing IPv6 with -6:

Here we have a good mix of IPv4 and IPv6 responses:
;; Received 500 bytes from in 0 ms
;; Received 504 bytes from 2001:503:ba3e::2:30#53(A.ROOT-SERVERS.NET) in 24 ms
;; Received 205 bytes from in 109 ms
;; Received 221 bytes from 2607:f590:f2::2#53( in 0 ms

The first and third requests used IPv4, while the second and fourth used IPv6. Again, this is a great demonstration of a DNS query in a mixed IPv4/IPv6 environment.

Notes and Caveats

  • There are a couple minor issues to be aware of when trying out our IPv6 test nameservers:
    If you attempt to delegate a CoCCA domain (such as .cx or .gs) to our IPv6-only nameserver, the following error occurs: “Host doesn’t have A record in responsible DNS zone. We will not add it to the registry.”
  • If you add our IPv6 nameserver to the delegation for a domain before the Custom DNS zone becomes active, the status message on the Custom DNS configuration page will continue to display “pre-activated” or “inactive”, even after the zone is loaded onto our nameservers. You may simply ignore this message, or remove the IPv6 nameserver, allow the zone’s status to update to “active”, then add the nameserver to the delegation again.

If you encounter other unexpected errors or issues when attempting to use the IPv6 test servers, please contact our Support team with the details of the error and we will investigate the problem.

List of IPv6 Nameservers

The current list of IPv6-enabled test nameservers for Custom DNS and Secondary DNS customers is as follows:IPv6

Nameserver IPv6 Address 2607:f590:f2::2

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