AT&T DSL using NVG599, Dynamic DNS and changing IP addresses
I read that AT&T regularly changes the IP addresses of residential gateway routers (modems). I have one of the newer (as of December 2017), AT&T U-Verse Arris NVG599 devices.
Does AT&T change my IP address of this device? If, "Yes", how do I setup a static IP address on this device?
Am I asked to pay extra monthly for a static IP?