I found XR500 only support DynDNS, No-IP and Netgear DDNS(actually no-ip).
Please add custom or more (e.g. DNS-O-Matic) ddns providers.
BTW, I take XR500 to replace my old N900. It has been 7 years (maybe 8) and still only get these three options.
Solved! Go to Solution.