HI I have a debian system (192.168.200.4), the firewall on that as is shown ... I am trying to run xclock from 192.168.200.2 using putty and XMING ...strangley enough with the following set up; xclock fails to start . As soon I change the policy on INPUT chain to ACCEPT , xclock starts working... Anybody would have any idea why this is happening... # iptables -L Chain INPUT (policy DROP) target prot opt source destination ACCEPT 0 -- 192.168.200.2 anywhere Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination ACCEPT 0 -- 192.168.200.4 anywhere ACCEPT 0 -- anywhere anywhere state RELATED,ESTABLISHED thanks ash - To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html