Hello all, What is martian source? I have created a simple firewall like below: iptables -A INPUT -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "Stealth Scan" iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP I have my LAN subnet, 1st ISP subnet and 2nd ISP subnet and I configure the routing table in order to let the different subnets can communicate with each other. Is it affect with my routing or not if I configure my firewall like this? $ nmap -sU -p 110 myservername Starting nmap V. 2.54BETA22 ( www.insecure.org/nmap/ ) Port State Service 110/udp filtered pop-3 Nmap run completed -- 1 IP address (1 host up) scanned in 1 second How can I configure my firewall to display like the result above ( nmap -sU -p 110 myservername)? Thanks, Chan Choth