Cisco DDNS update to DNS-O-Matic returns OpenDNS Page Not Found

Question

I have a Cisco 857 router which I am trying to configure OpenDNS on.

DDNS over https is a bit awkward on this router as it doesn't easily support HTTPS, so directly updating OpenDNS isn't a good option.

OpenDNS provide another service called dns-o-matic, which does support HTTP updating, but i am having a strange problem. When my router calls the dns-o-matic update URL, i get an OpenDNS page not found response. If however I copy the URL for the Cisco log, paste it in to my browser, I get a successful update!

In my config i have:

ip ddns update method dynamicdns
 HTTP
  add http://[username]:[password]@updates.dnsomatic.com/nic/update?myip=<a>

interface Dialer0
 ip ddns update dynamicdns

In the log I see:

HTTPDNSUPD: URL = 'http://[username]:[password]@updates.dnsomatic.com/nic/update?myip=[ip]'

then in the response I see the HTML for the OpenDNS Page Not Found page.

When I run this through a browser, I get:

good [ip]

and when I check my DNS-O-Matic status page, the IP has been updated, and also passed through correctly to OpenDNS!

So I don't appear to be having a name resolution issue, otherwise there would be no response.

DNS lookup from both my laptop and the router resolved the update URL to the same IP...

What I can't find is anything that may give me better logging of the actual HTTP protocol packets. I can't wireshark it because this is going over the ATM/Dialer out to my ADSL...

Does anyone have any suggestions what I am doing wrong, or how i could get some better info on what's happening?

Answer 1

Are you sure that you see OpenDNS page saying that page is not found? In my opinion, Cisco routers have problem with parsing username in the form of e-mail address. They recognize @ sign as the end of credential section and try to use mail server name as a ddns server name. So, in my logs I see 404 page but coming from e-mail system.

Answer 2

La configuración queda asi: (Cisco 881)

ip name-server 208.67.220.220
ip name-server 208.67.222.222
ip ddns update method OPENDNS
 HTTP
  add http://usuario_opendns:[e-mail]/nic/
update?=myip=<a>
 interval maximum 1 0 0 0
 interval minimum 1 0 0 0

Despues en la interfaz wan, en mi caso fa/4

ip ddns update hostname updates.dnsomatic.com
ip ddns update OPENDNS