Dyndns2 protocol specification?

Question

I’m seeing a “DynDNS2” protocol referenced a lot but I have a hard time locating its specification. AFAICS, RFC 2136 is not versioned on the protocol level so I’m inclined to rule that one out. Somehow I can find numerous implementations of DynDNS2 but the repos I’ve browsed don’t link to a canonical document either.

Example: https://support.google.com/domains/answer/6147083 – that’s Google claiming they support this protocol without further explanation.

Where can I find the official specification of DynDNS2?

Who is in charge of its standardization and development?

Answer 1

The link (now) shows how to do so "manually":

https://username:[email protected]/nic/update?hostname=subdomain.yourdomain.com&myip=1.2.3.4

And gives more specs. You should check the link to the support page again and click the Using the API to update your Dynamic DNS record

Example HTTP query:
POST /nic/update?hostname=subdomain.yourdomain.com&myip=1.2.3.4 HTTP/1.1
Host: domains.google.com
Authorization: Basic base64-encoded-auth-string User-Agent: Chrome/41.0 [email protected]

Also you need to add the User Agent header to make sure your call is not ignored or worse, your client is blocked.

At source forge you can find a list of these dynamic DNS "protocols".

Answer 2

Dyn.com has quite good documentation on their site including flow diagram, update api and return codes

Answer 3

The RFC 2136 spec is an extension of the DNS itself and used by nsupdate command. It's complicated and is used by sysadmins.

Routers are using just a plain HTTP GET requests to some DDNS provider. Their urls are looking the same as original Dyn.com have: /nic/update?hostname=[DOMAIN]&myip=[IP].

See:

• https://openwrt.org/docs/guide-user/services/ddns/client
• https://sourceforge.net/p/ddclient/wiki/protocols/