Open ports with a dynamic IP adress?

Hey!

I'm trying to start a server, and to be honest, I'm a noob regarding to network and ip's.

But here is my problem.

I'm trying to start a server in minecraft, but I can't get it working. Minecraft is using 25565 as a port, I can easily open the port in the router, but when I go to canyouseeme.org it can't connect to it. By the way, I have tomato firmware, and I put the server adress as my LANadress from Ipconfig. I have even tried to enable DMZ but it does not work.

I have a dynamic IP, but it can easily be solved by using DynDNS.com - Free Domain Name, Managed DNS, Email Services, to redirect to my external IP.

Why can't I open ports?

Thanks

Kind Regards
powerfull499

 

Up until 2 weeks ago I thought Minecraft was just some online version of Minesweeper.

 

Well, thanks for the answer.. I guess.

Can anybody help please xD?

 

It sounds like your router port may be open, but the traffic doesn't know where to go. If the software (Minecraft? Don't know what that is) is installed on your server which has a LAN address, you have to have your router which has a WAN address point the traffice to it. This is usually done by port forwarding. That's what I think your problem is. If you have a Linksys router, it is really easy to setup port forwarding.

 

Thanks for the anwer.

I tried unplugging the router, and plug it directly into the modem, but no ports are open!

That means, that my ISP is blocking something, right?

Or what?

Thanks.

 

No not necessarily. what kind of router do you have?

 

Actually, sorry, I didn't fully read your post....If you plug a computer directly into the modem and can get internet access (you often have to reboot your modem to make this kind of swap work) and the port still doesn't work, then you might have a conflict with your ISP. It might also be a software firewall such as Windows firewall or your AV software that is blocking. Remember you have to create exceptions for those as well depending on your software.

 

I'm going to ask the stupid question for the day;-

I only see mention of the router and the port settings on there, are you running a third-party software firewall on the server too? You could find that the software firewall is blocking the port..

Bah beaten to it while I typed lol

 

No problem Trixster. We are both on the same page. I think that either software firewall or port forwarding on the router is not configured. Those are the only things I can think of that stop port traffic. ISP's don't normally block obscure ports.

 

Thanks for the answers.

It is not a firewall problem or AV, because I tried to turn them both off. I can easily acces the internet if I plug it directly into the modem, but I can't get acces to any ports =S. So it makes no difference if I'm using the router or mode.

 

What is your router make/model?

If your trying to run this so your friends can connect via the net then the servers IP should be the WAN IP not your LAN IP. And, imo, your pc should be a static ip rather than a dhcp allocated one, if indeed that is the case.

Also, are you checking the port when the game is running, most sites will not see an open port unless there is an app running with it open. Like if I use shieldsup to check my torrent port, even though it is set in NAT and NOD, it will always report as stealthed until I run the program - then everything is smooth sailing.

 

Hmmm..okay, i'm not sure exactly what the aim is really as I knows nothing about Minecraft or fully understand what you are trying to accomplish but I just have a hunch that your answer lies in post #4; which speaks about portforwarding. You mentioned still having issues when directly connected to the modem. Then the modem/ISP might be the cause of your issues.

Can you log into the modem and forward the appropriate port to your Server? If canyouseeme.org says the port is not open then most likely it's either not forwarded properly or it's being blocked, possibly by ISP or software firewall as Ghost mentioned. And if I were you i'd totally uninstall those firewalls/antivirus programs to test...trust me, I know what i'm saying...been there.

BTW +Rep to Ghost. Helpful tips!

 

Hey Thanks Makaveli! 1 point to you as well. Yes I really feel this is a port forwarding issue. You can use a LAN IP if you have NAT going and port forwarding setup from your router (external address) to your LAN address (of the server). It is a very easy setup in the router depending on your model.
If Minecraft will allow it, you can try switching the port in the application to port 80, which will definitely be allowed through your ISP. If it works, try another random port above 1000. This could signal that your ISP is blocking specific ports. Then you can call them and have them monitor traffic to and from your computer to see what is coming and going.

 

Another important question I just thought about is what is the operating system of this computer? If it is Vista, and maybe even Windows 7 does this, there are built in firewall rules that lock your computer down depending on what kind of network you lable it when you set it up. Basically, if you labled it a Public Network, it would lock down all of your ports so no traffic could come in that wasn't first requested. It is a long shot, but we haven't heard the real specifics of the server computer and router so I am just drawing straws.

 

Thanks for the answers.

What I'm trying to accomplish: Be able to open ports!

I have an Asus RT-N16 with Tomato firmware. I have tried to turn the firewall off, and uninstalling my AV-software. My computer has a dynamic IP. As I said, I have tried to connect DIRECTLY to the modem, then scanning for open ports, and it found nothing - it even didn't find port 80.

I don't know what's wrong ?! It has nothing to do with my computer, firewall etc.

Is it even possible to open ports with a dynamic IP?

 

You can use a dynamic ip, but because it is dynamic it could change thus rendering the ports that you'd opened useless until you changed the ip they pointed too. That is why I mentioned switching your pc to a static ip for your network, simple ease of use.

This is for the N15 setup, but it is basically the same for your model too - although no doubt the gui will be totally different as you have switched firmware.

PortForward.com - Port Forwarding VNC on the Asus RT-N15

Have seen a few reports that the Asus firmware 1.0.1.2 PF was working all ok..

 

What are you using to scan for open ports? I know when I was trying to open ports on my router that canyouseeme.org only found ports with services running on it. So even if you had the port open but the service was not running it would say that the port was closed. Is the server running when you are trying this?

 

OK. I have checked my work network, which uses a static IP address block and my home network which uses DHCP with DYN DNS. canyouseeme.org shows certain ports open on my work network but the same ports closed on my home network. And I know traffic is going over them. I think the problem lies with either DYN DNS or your ISP. Maybe port scanning doesn't work with DYN DNS, or your ISP is blocking port scanners. I would contact your ISP and have them monitor your traffic and answer your questions regarding blocked ports. I can't think of anything else that may be causing the problem.

 

Way to go the extra mile. +1 for the link. Hope it helps. I'm out of ideas.

 

Thanks for the answers.

I have found out, that I can open UDP ports, but not TCP =S. It's really weird! Is it the ISP who is blocking TCP-ports?

 

Honestly don't know, imo it's quite rare for that to happen..

I've used umpteen random ports noumbers that I have thought of through the years as well as game ports and not once have I had an isp block them.

 

I'm not sure I understand you. You can't open TCP ports on your router? That doesn't seem right. I still think your first step should be to call your ISP and find out what ports they are blocking if any. Rule them out of the equation and then work from your modem back to your computer.

 

Most all ISP block ports to prevent end users from running servers. I always use ports >1024, these are normally not blocked. Now you do not want to use ports related to ports used for game servers, these are also blocked by some. Some ISP will allow you to upgrade to a Business class service, then the normal ports are open.