In the portal it is Systems > Network/Dynamic DNS and it is per machine, but I am not sure this is where your problem is. Can you please enable webconfig debugging just before you access the menu:

touch /var/log/webconfig/debug.log

chown webconfig:webconfig /var/log/webconfig/debug.log

touch /etc/clearos/webconfig.debug

Then access the DDNS menu. After a bit, turn off the debugging by removing the file /etc/clearos/webconfig.debug or hiding it.

Then have a look at the log, mainly for ERROR lines. There are normally one or two but the problem may stand out and it will relate to quite a few lines around the error. Please don't post the log in-line as it can be big, but you can attach it as a file.

Hi Nick , all my other clearos servers with dynamic dns is working. So not sure if one can stop services on the portal for only one clearos server. In fact I am not sure where to go to on the portal to do this. There are no outbound filters active on the affected clearos server.

Mine goes straight in. Do you have DDNS enabled in the portal? Do you have any filtering upstream of you which could be blocking it from connecting to the ClearSDN servers?