ADSL connection (PPPoE) not possible?

[Ubuntu Forums Post]

if you try to set up an adsl-network with firewall-router and ethernetcards (dhcp), it gets more tricky. on my boxes, i am able to ping all sites, but no web site is displayed. i guess it is a dns-problem but i can't really solve it as the resolv.conf gets rewritten by the system everytime i use the net. very frustrating.... especially as everything works with vidalinux/gentoo.