I have setup the 2860n with a dynamic dns (dtdns.net) it is updating the wan IP correctly (checked logs via telnet also seen it change on dtdns) I also have opened ports for RDP and pointed to the LAN IP.

if i use RDP to connect to the current WAN IP then i can connect and log in and all works. however if i use the dynamic DNS address it will not connect. i must be missing some kind of security setting somewhere. can anyone advice me?

ps its not just RDP but also other port services i have opened are not working when using the DDNS adress.