You can get these routers for little money and they are perfect for sitting in front of a firewall system with little hassle. (perfect for cisco, openwrt, iptables, pfsense etc)
*this also works with DG934G routers as you can reflash them to DG834v3, loads on ebay branded Sky for £5-10
All you need to do is access a hidden option screen. Open up the configuration in a browser and change ‘setup.cgi?nextfile=start.htm’ to ‘setup.cgi?nextfile=mode.htm’ You can then select Modem and Apply.
Now setup the firewall that is behind the DG834G to connect via PPPoE on port1.
Reasons for having this setup: stop double NAT, firewall has a real external IP, no more DMZ or invisible proxy.
post taken from equk’s miniblog