Iptables Input Rules

INPUT Rule :

iptables -I INPUT -i eth0 -p tcp -m tcp –dport 5900 -j ACCEPT # vnc
iptables -A INPUT -i eth0 -p tcp -m tcp –dport 21 -j ACCEPT # ftp
iptables -A INPUT -i eth0 -p tcp -m tcp –dport 22 -j ACCEPT # ssh
iptables -A INPUT -i eth0 -p tcp -m tcp –dport 445 -j ACCEPT # cifs
iptables -A INPUT -i eth0 -p tcp -m tcp –dport 139 -j ACCEPT # netbios-ssn
iptables -A INPUT -i eth0 -p udp -m udp –dport 137 -j ACCEPT # netbios-ns
iptables -I INPUT 2 -i eth0 -p udp -m udp –dport 138 -j ACCEPT # netbios-dgm

Drop everything else :

iptables -A INPUT -i eth+ -p udp -j DROP
iptables -A INPUT -i eth+ -p tcp -m tcp –syn -j DROP