I can't access port from outside

Question

I'm using a dedicated server on aruba with ZyWall firewall. I have two ports listening in the server, using telnet from inside I can connect to both the ports. If I try to telnet from outside I can access only to one of them.

I have not internal firewall, and I don't understand how I can see if the ZyWall is blocking the port access or it is forwarding all connections to that port to another ip.

Have you any suggestion?

Answer 1

I found the solution. I accessed the firewall web interface from a firefox installed in the dedicated server behind the firewall (the web interface is not accessible from outside), then I made two steps:

• I added a rule on which I permit the access to the target port. I made this using the "Service" tab in the Security->Firewall menù.
• In the matrix between LAN, WAN, DMZ etc.. I modified the rule "from WAN to LAN" and I added the rule made in the previous step.

Now it works!