Hi! I've installed a mdk 10 on a 2 nics machine to act as firewall/proxy. All works fine (ip routing, dns resolution, web proxy), but after some minutes all the comunication stops...wait some time and then restarts...
While this time if I run route command I get the first two lines:

192.168.3.0 * 255.255.255.0 U 0 0 0 eth0
127.0.0.0 * 255.0.0.0 U 0 0 0 lo

and after more than 1 minute I get the last line

default 192.168.3.1 0.0.0.0 UG 0 0 0 0 eht1

(When comunication works the route command shows the three lines immediatly).

The same with arp.

I don't understand why...

Thanks for help!

There seems to be a misconfiguration here.
Make sure your 2 nic's are on different networks, also which do you want as default gateway, eth0 or eth1?
I assume eth0 is internal, eth1 external thus default gw?
192.168.3.x should then go through eth0 and have nothing to do with eth1.

Post output of 'ifconfig' please, and also tell me where your internal network is.

Thanks for the suggest! I resolve the problem! I forget the route for the adsl modem (the default gateway)

192.168.3.1 * 255.255.255.255 UH 0 0 0 eth1

I understand it's better to have two separate network, but I'dont know how to change the modem ip and I don't wont to change all the my 120 pc ip.

Thank's