Hello jimp,
thanks for your answer.
yes, that's what I checked first, but all the settings are ok (ip, dns, gw). Even when I config static settings I'm not able to get a connection anymore.
It's always after the first reboot.
I now tried smoothwall, and there I have no connection issues, but I prefer pfsense ;)
Another error I had sometimes is that after disconnecting wan or setting anything up on network interfaces, the web ui had some problems an I had to reboot the web ui.
Maybe a driver issue?