AT&T U-verse with DD-WRT router in DMZ mode
I recently got AT&T’s U-verse service at home and have been enjoying it so far. The internet has been working much better than my Mediacom service had been doing. My only issue was that I wanted more control over the router and I wanted to setup VPN access into my home network. So, I installed DD-WRT on my Cisco E4200 wireless access point/router then got the AT&T setup in DMZ mode to pass traffic to the E4200.
This setup was working great for almost all aspects except when I would VPN into work or even do a SSL remote desktop session outside my network. After about 5 minutes the remote desktop session would become unresponsive and I’d have to reconnect. This was driving me crazy because I couldn’t work for more than 5 minutes at a time. I did a bit of Googling and found the answer on the following site:
Basically, the DMZ mode on the AT&T router was causing the DD-WRT to renew it’s lease every 5 to 10 minutes. The DHCP responses were being blocked by the DD-WRT firewall.
Adding the following command to the DD-WRT firewall fixed the problem and I haven’t had a remote desktop timeout since:
iptables -I INPUT -p udp –sport 67 –dport 68 -j ACCEPT
(Click the Administration tab, then Command tab. Enter the above command in the text box and click Save Firewall then reboot.)
Be sure to check out the above website where I got the fix from. They have a lot of tips and fixes for other issues as well.