Dynamic DNS services for remote access to computer on our network?

Hi --

 

I'm trying to get a domain names set up for a few of our home devices so we can log in remotely. We've been trying NoIP.com to handle the dynamic DNS, and it works most of the time: we can log into mycomputer.noip.net (fake example), and it correctly maps to our IP address from Xfinity (e.g. 69.181.111.111 (also fake). However every 8 to 12 hours, this breaks, and the mycomputer.noip.net domain name ends up pointing to another address e.g. 142.123.123.123.

 

This appears to be a DNS propagation issue: I can still log in via the 69.181.111.111 address directly, and if I force the NoIP client to re-broadcast its DNS mapping, the mycomputer.noip.net resets to 69.181.111.111 within a few minutes. However obviously having to do this by hand defeats the purpose of dynamic DNS services like this so I'm hoping someone here can help out.

but occasionally breaks: 

 

We have a Netgear CM1150V Cable Modem (self-bought) and an Airport Time Capsule that is our home router. The Airport Time Capsule is configured to receive its IP address via DHCP (rather than "Static" or "PPPoE"), and is configured in router mode "DHCP and NAT".

 

The NoIP folks haven't been able to shed much light on this, other than that they believe there is a second DHCP server that is periodically pushing out a different IP address for mycomputer.noip.net, or that there is a "double NAT" issue at play. Apple's Aiport Utility software usually complains if it notices a double NAT and I haven't seen any such warning. However clearly there are 2 DHCP servers at work: the Xfinity one that is sending us our IP at home, and our Airport which is serving up IP addresses to our internal devices. Could this be the problem?

 

Thank you in advance for any pointers or tips you might have, or even examples of other 3rd party dynamic DNS providers that you know work with the XFinity network.

 

Best regards,

 

Ramon