Hello everyone....

I want to dedicate a computer as a firewall for my LAN using IPTABLES.

On the firewall machine i have 2 network cards running. eth0 (internal lan) has an ip range of 192.168.30.0 and eth1 (external lan) has an ip range of 192.168.20.0

eth0 also runs a dhcp server for the machines behind the firewall and eth1 is a dhcp client from the external lan (i want to seperate my lan into 2 networks, my main gateway is a zyxel isdn router on net 192.168.20.0 which also acts as a dhcp server for the firewalls eth1)

My main problem is that even if the firewall is not started, i cannot access the external lan from the internal lan, but from the firewall box itself i can ping both networks. Can it be that is a routing problem (im not very good with routing). I run SuSE linux 7.3 kernel 2.4.16

Incase its not a routing problem, what else could it be, im really a bit lost here about this subject. Any help would be really welcome.

I apologize if my problem is not directly security related, so forgive me if my post is not in the right place, please tell me if its in the wrong place too.