Hi,
I've just signed up for your service today. I have a Technicolor TG703 router.

I have followed the instructions here: https://www.dynu.com/DynamicDNS/IPUpdateClient/Technicolor

(I performed both the telnet and the web configs successfully.)

However after I "apply" the web config, I see following on the admin screen:
There is an error with Dynamic DNS. Please check your connection and the username/password.

and in the logs:
Oct 13 10:48:56 DYNDNS Update failed for client dyndns_0 (Authentication failure), host jscrane.dynu.com has not been updated

I've attached a screenshot of the web config.

Thanks,
Steve

1. Check if the hostname you are using in the router is the same as the one in your Dynu account.

2. Check your password.