HI,
i want to set up your dynamic dns service on my home netowrk. The router i have is a technicolor T7210. I have been following instructions you provide here; https://www.dynu.com/DynamicDNS/IPUpdateClient/Technicolor

However I cannot connect via telnet (i opened the telnet on my Windows 10 pc when connected to the wifi network and entered 'telnet 192.168.1.254' but i get a 'connect failed' error every time). Any ideas on how to proceed?
Thanks.

192.168.1.254 may not be the default IP for the router. Have you tried 192.168.0.1, 192.168.1.1, 10.0.0.1?