you can use the following command in you linux server using your shell, you can access the shell terminal by starting a ssh session, once you have started the SSH connection, send this command for checking the iptables configurations settings in your server, the command to use is iptables -n -L once you have executed the command, you will see a list that could look like this: 
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination