So I’ve been using U-Verse internet service for almost a month. I experienced occasional dropped connections and could not find the source. As usual, AT&T’s technical support has been completely useless.
I was able to watch Netflix on-demand and download large files without issues for the next 2 weeks after the installation, but then again dropped connections started to reoccur to the point that it was really annoying.
The symptoms of dropped connections reoccurred, unfortunately. I decided to research further and found an interesting article about the DHCP lease time for routers behind the 2Wire router provided by AT&T. By the way, my router was assigned the WAN IP as it was in the DMZ+.
I went ahead and added the following configuration to the firewall:
iptables -I INPUT -p udp --sport 67 --dport 68 -j ACCEPT
I then rebooted both routers and voilà. Things are now back to normal.