There are three IPs to retrieve for portforwarding.
Private IP (the IP of your computer in your network).
Public IP (the IP of your network).
Gateway IP (the IP of your router in your network).
To retrieve the private IP and the gateway IP:
1. Click on Start.
2. Click on Run.
3. Type ‘cmd’ (on Windows NT and later) or ‘command’ (on Windows ME and prior).
4. Click on OK.
1, 2, 3 and 4 are equal to opening a command prompt.
5. Type ‘ipconfig’ in the command prompt.
6. Press enter.
7. Your IP addresses should now appear. The default gateway is your gateway IP and the IP-address is your private IP.
Connecting to your router:
1. Open your internet browser.
2. Type the gateway IP in your address bar.
4. The router configuration should appear now.
If you need to log in, log in using your account data from the ISP (Your network administrator will surely know what the username and the password are for this account, if you aren’t the network administrator).
Once logged in, you’ll need to configure your port forwarding settings (my explanation may differ from most routers, however, it might help).
If you’ve a menu then go search for NAPT, NAT, firewall, game settings, port forwarding, port translation, etc. Click on it.
Now a list should display which is most likely empty. If you’ve an ‘Add’ button then click on it. Now some details should display to fill in. I recommend to use the help available in your router settings or the manual which came with your router for this instead of relying on me. In case none of both are available then try finding out things yourself.
The protocol: the protocol should be TCP or TCP/UDP or ‘Both’ or ‘Every protocol’. Whatever options you’ve, be sure that it is either everything or just TCP. Without TCP Eclipse will not work.
The incoming/outgoing address: if this is there, then fill in your private IP.
The incoming/outgoing port: fill in the port you want to open (check Server/data.ini for the port for Eclipse).
If you’ve something like begin and end, then fill in the same port in both. (Begin and end will allow you to open port ranges like all ports between 4000 and 6000 and those included).
Translate to: if you’ve something like this, it should be your port if you can only type in five characters at max. If you can type an IP-address, type the private IP, if you also need to type a port, type the port.
It should always be something like this.
After adding your port, click on OK or whatever button is available and reboot your router.
Gaining the public IP:
Go to http://www.ipchicken.com/ and get the IP.
I’ve explained IP distribution already (what IP to use when connecting at a specific place).