The following commands will allow you to open tcp or udp ports on the server.
Before using commands for opening the port please make ensure the specific port is already opend and what is the use of that port.
you can verify the port with command
netstat -nap | grep : <port no>
1.you can open TCp port with
iptables -A INPUT -p tcp –dport <port no> -j ACCEPT
2. You can open UDP port with
iptables -A INPUT -p udp –sport <port no> -j ACCEPT
3 service iptables save
and for flushhing iptables us