I have a Linux PC I would like to use as a firewall. I have configured the router part of it:
1] enabled packet forwarding in the sysctl.conf file
2] set up NAT with the MASQUERADE option because my Internet connection is configured via DHCP
However, I set the following rules in iptables:
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
I then save this to my /etc/sysconfig/iptables file and started iptables, /etc/init.d/iptables start
I dont understand how I am still able to connect to the Internet from another PC behind the firewall.
---------------- ----------- ------------ ------------------
| other pc |-----------| switch |-----------| firewall |-------| DSL modem |
---------------- ----------- ------------ ------------------
my first ASCII art ... thanks in advance ...