LAN gaming issue with Arris NVG510
Just got my U-verse set up, and all is well except for one area, and that is gaming over my LAN. I didn't change my settings with my computer, but I did get a new modem/router (Arris NVG510). There seems to be some firewall setting preventing any one computer from communicating with another (for gaming over the LAN), but I don't know how to get around this. My main computer is wired into the modem, but my son's computer is Wifi. I tried calling AT&T, but they weren't much help. I would greatly appreciate any help in this matter.