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First off, my router is a D-Link DIR-655, firmware v2.07. I'm trying to port forward port 25565.

My port forward settings are this:

Port forwarding

However, when I use this open port checker, it claims that I don't have that port open. It looks like this, without the blurred out parts:

Not working

Why is this? How can I fix it?

Added note: The way I want to use it is by my IP ( I have the software installed to do so (I'm using a minecraft server, connecting through minecraft), but I can't enter my IP in the IP address field, it says that it's out of the range of the LAN.

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Do you actually have a machine at with a listener open on port 25565, and have you verified that that machine does not have that port blocked in its firewall software? – Spiff Jul 28 '12 at 7:35
My firewall has an exception built in for port 25565, so the firewall isn't it. I'm trying to run a program that uses 25565, it's not another machine. – Frank Jul 28 '12 at 7:44
Okay, so the machine that you're running the Minecraft server that machine at And was the Minecraft server running on port 25565 at the time you used the open port checker? – Spiff Jul 28 '12 at 7:57
No, the minecraft server is my external IP ( plus 25565 (so the full address to connect is When I typed my external IP into the box, it gave me an error about how it was out of bounds of my LAN address – Frank Jul 28 '12 at 7:58
have you proved whether it's your LAN or windows firewall? you prove it by doing like nmap, from one computer to another's socket(IP:port), it's on the LAN, do it from another machine. – barlop Jul 28 '12 at 7:58
up vote 1 down vote accepted

In your DIR-655, try disabling that Port Forwarding rule and entering the same information on the Virtual Servers page instead.

Then make sure you have your listener (Minecraft server) running on the machine you set up the port mapping for (the machine with LAN private IP address, apparently) and re-run the open port check web app you were using.

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Is the port open on your computer? It might be the router is forwarding the port but your computer isn't hosting anything on that port. What OS is your computer running and maybe we can go from there.

But make sure whatever service you are running that is listening on 25565 is actually listening otherwise it'll show the port is closed.

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My OS is windows 7. I am running the tool that uses 25565. – Frank Jul 28 '12 at 7:42
what about windows firewall? or internet security software? – MaQleod Jul 28 '12 at 7:49
I added an exception to the firewall, and have no antivirus at the moment, I'm not installing any until I get this worked out so I know it's not responsible for it. – Frank Jul 28 '12 at 7:50
does it work inside your LAN, from another private IP address? That way you can at least separate the computer from the router so you know where to focus. – MaQleod Jul 28 '12 at 7:55
Localhost and in address bar defaults to port 80. That doesn't mean your port 25565 is open. Do a netstat -an in command prompt and see if it shows up for UDP and TCP for the port either on localhost,,, or .. What does it show? – richardhsu Jul 28 '12 at 8:30

The following are just some tips from my experience with results that show whether a port is open or not:

1) Use at least two different websites. The other port checking website I would recommend is In addition to telling you if the port is open or closed, it also usually gives you an error message.

2) Use a desktop program called PFPortChecker which you can get from here: Though it checks if the port is open via the same external ip address as the websites do, it is more accurate. For example, in my case, the website that you are using, plus the other one I recommend, would both tell me that port 21 is closed. I would then check the port on PFPortChecker, and it would tell me that port 21 is open. Then, when I would go to either website and check on the port, it would now show that it's open!

Part of the problem stems from checking the same port repeatedly as previous attempts are still checking or listening to the port and the connection has not been closed, so future immediate checks show them as closed.

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