The REST API specification is available at https://dynv6.github.io/api-spec/


We implemented the dyn.com Remote Access API that is also known as the Members NIC Update API or DNS Update API. It can only be used to update the IPv4 address of a zone.

To use the endpoint https://dynv6.com/nic/update please set the server in your client to dynv6.com.

Update API

The Update API supports updating the IPv4/IPv6 address and the IPv6 prefix as well. Whenever your IP address changes, send an HTTP GET request to the following URI:


You can use http:// instead of https:// (although not recommended).


Name Requirement Description
zone mandatory Your dynv6 zone name.

Alternative parameter names: hostname and Hostname

token mandatory An HTTP token for this zone.
ipv4 optional Updates the IPv4 address (A record) of your zone. One of the following values:
  • Your IPv4 address in dotted decimal format (e.g.
  • auto to use the clients address
If empty or unset, the current IPv4 address is kept unchanged.
ipv6 optional Updates the IPv6 address (AAAA record) of your zone. One of the following values:
  • Your IPv6 address. If it includes a prefix length like /64 and you omit the ipv6prefix parameter, then your prefix will be updated as well. (e.g. 2a02:12ab:34c:ef::123/64),
  • auto to guess the IP address from your client address
  • 6to4 to generate a 6to4 prefix from your IPv4 address
If empty or unset, the current IPv6 address is kept unchanged.
ipv6prefix optional Updates the IPv6 prefix of your IPv6 records, but not the AAAA record of the zone itself. Use one of the following values:
  • Your IPv6 network in CIDR notation (e.g. 2a02:12ab:34c:ef::/64),
  • auto to guess the prefix from your client address
  • 6to4 to generate a 6to4 prefix from your IPv4 address
If empty or unset, the current IPv6 prefix is kept unchanged.

Note on auto values

If you set ipv4=auto or ipv6=auto/6to4, you might want to use a different URL to enforce a specific IP protocol version:

  • for IPv4-only
  • for IPv6-only

Use our update script

We provide a small script that updates your address at dynv6. You can run it with:

token=your-token ./dynv6.sh example.dynv6.net


Upload your SSH key on the keys page and connect to api@dynv6.com.

To execute commands you can use our interactive shell (pseudo-terminal) or run commands directly. Use TAB to learn the command structure.

Features implemented

  • Listing and adding hostnames
  • Listing records
  • Updating the IPv4/IPv6 address of a dynv6 hostname
  • Adding and updating A/AAAA/TXT records

Features coming next

  • Adding and updating CNAME/MX records
  • Removing records

DNS Update


First, you need to generate a TSIG key.

Then you need a client application to update DNS enties, like nsupdate (or nsupdate.exe on Windows). It is part of the ISC BIND distribution and generally available for most operating systems.

Note: You can use any RFC2136 compliant software to manage your DNS entries, nsupdate is just one example. Another viable option, especially if you only want to obtain free Let's Encrypt certificates, is to use lego (and software based on lego, like Caddy)


If you've meet all prerequisites, you can for example, update the A and AAAA records for yourhost.dynv6.com like so:

nsupdate <<EOF
  server ns1.dynv6.com
  zone yourhost.dynv6.com
  update delete yourhost.dynv6.com A
  update add yourhost.dynv6.com 60 A
  update delete yourhost.dynv6.com AAAA
  update add yourhost.dynv6.com 60 AAAA ::1
  key hmac-sha256:_123._tsig.dynv6.com YourSHAREDsecret==

This alters your host yourhost.dynv6.com using the TSIG key named _123._tsig.dynv6.com.


  1. The actual update set are the lines 2-9 (between <<EOF and EOF).

  2. The server command (l. 2) is optional for recent versions of nsupdate. Very old versions might need an IP address, in that case use server

  3. We require the zone command (l. 3) for authorization. Your updates will be rejected, if the zone does not match the provided key (l. 8).

  4. Before adding new entries (update add, ll. 5/7), you should cleanup existing records (update delete, ll. 6/8), unless you really want to end up with multiple records.

  5. The TSIG key must be used in the form algo:name secret (l. 8). It must be the last entry in an update set.

  6. With nsupdate, do not use empty/blank lines to separate statements: these are interpreted as send command, and your update will likely fail. You can use ; at the beginning of a line, though (a semicolon indicates a comment and will be ignored).