How to set a network interface as 'trusted' on Centos 6 (with multiple interfaces)

Question

I have a box with two wired network interfaces. On Centos 5 I could run the setup command in console and set which interface is trusted and which not in the firewall configuration (e.g. eth1 trusted, eth0 - not). A few hours ago I have installed Centos 6 instead 5. When I go to the same Firewall Configuration through the setup command, the configuration interface is a bit different and I can not set the 'trust' per interface. There is just eth+ (which I think sets both the interfaces as trusted).

So my question is: how do I set which interface is trusted and which not on Centos 6?

Thanks in advance!

UPDATE

Based on quanta's suggestion I entered the two commands in the console but it didn't help. Then I tried to service iptables save and service iptables restart with no changes too.

Then I did the following:

I created a file /etc/sysconfig/iptables_eth1_trusted with the folowing content (eth1 is my LAN interface, and yes, when I tried quanta's commands in console I also used eth1):

-A INPUT -i eth1 -j ACCEPT
-A OUTPUT -o eth1 -j ACCEPT

Then I launched setup in console and in the 'Firewall configuration' I went to 'Custom Rules' and added the following rule:

Protocol Type: ipv4
Firewall Table: filter
File: /etc/sysconfig/iptables_eth1_trusted

I saved it and it worked as I wanted to.

I am quite new to linux and my iptables knowledge is very poor, so thanks to quanta for the rules, they were correct.

Answer 1

Selecting a device as trusted means all traffic over this device is allowed. So, try this:

iptables -A INPUT -i eth0 -j ACCEPT
iptables -A OUTPUT -o eth0 -j ACCEPT