Hi, I (for some unknown reason) was thinking that the firewall that your clients > used was a Linux box which had a 2nd hardware firewall connecting it to the > net. As such I did not take in to account that the host that you would be > running this rule on might not already be set up to > forward traffic. My clients gateway is set to squid proxy and the squid proxy 's gateway is set to the firewall. I want to run the rules on my squid box and there are no other rules on it. Except the ones that i send in my previous mail. As such, do you have any other firewall rules set up or policies on chains > set to DROP traffic? Also you will need to make sure that > /proc/sys/net/ipv4/ip_forward is set to 1 thus configuring your server to > forward traffic. You will have to forward traffic as traffic is coming in to > your server and then being redirected / forwarded to another server. This > could possibly explain the ""filtering that nmap is reporting as I'm not > sure what type of error will be generated by trying to forward and then > being DROPed. I expect that the traffic will just look like there is > something in the way, not a reject or no route to host or any thing like > that. Yes no extra DROP rules My squid box has only one interface so there is any neeed of enabling forwarding on it. ?? Anyways i enable forwarding but still it does not works. Thanks