Blocked Ports

Hello all. My 2 friends and i had a lan a while back (they braught their comps to my place with a router) we got it all hooked up and had fun on our mini lan. When we dis=assembled and they went home something strange happened. Im no longer able to direct connect to one of them. With file transfers and things it says we cant connect and we cant even stay connected to each other on online games. Somebody suggested to me that our lan might have caused ports to be blocked preventing us from connecting. I was just wondering if this was possible since i dont use a router on my computer. If so does anybody know how to unblock ports so we can connect again? help is much appreciated

Basically how a network works:

View this Basic Network


The WAN comes from the outside to your modem/router. The LAN is what you have on your side of the modem. So if you take one of those computers out of the LAN and set it up to a different modem at your friends house it is no longer on the LAN, it is part of its own LAN.

There is the IP address that comes from your ISP, whether it is static (a fixed IP #) or Dynamic (it changes based on a number of preset addresses your ISP can use.)

Then when you create a LAN you create a batch of IP #'s designated for LAN's, for instance, 192.168.0.1 would be your router (which is actually a computer.), 192.168.0.2 would be computer #1, 192.168.0.3 would be computer #2, etc like this. All under a subnet of 255.255.255.0....

These IP's only work on the LAN, if someone runs a port scan on your computer setup, then they would hit the router based on the IP that your ISP has you on. There is one way to make this LAN larger - using a VPN (Virtual Private Network) which opens a secure tunnel across the WAN. This also can jeopradize your security depending on how you have it set up.

Your router also acts as a firewall in that someone scanning your router will not be able to detect any info on you (like active ports, which processes you are running, and what OS you are using.), and most you can set to not respond to pings, which makes them even more invisible. This is good though. If you set it up so that you can get into your friends LAN game - ie, make the Game server run in the DMZ - Demilitarized Zone, you are essentially letting any wanna be hackers hack you in about 2 minutes. So I wouldnt advise doing that unless you have a secure server computer set up outside of the Router in the DMZ and you know how to secure it, and I wouldnt advise using a windows OS for something like this - and one note - there has been some real serious game server hacks recently, most using the Game Spy. I know they found a big one in all versions of Unreal, that is pretty serious.

I think what your problem is that you took the computer out of the LAN and now you cant connect to it.

I read over your question again and I am not sure what you mean by "dissasembled" your LAN. Are those computers still with you? or did your friends take them home with them?

no my friends took them home with them. All we did was, my friends brought their computers to my house. One of my friends also brought his 4 port router. We set all the computers up and plugged them into the router and got them all working on our own little network. We werent worried about hacking and stuff because none of the computers or the router were hooked up to the internet. Hmmm perhaps in using the wrong word. HUB may be a better word. We set it up played some games on tcp/ip through the HUB and then the next day, my two friends took both of their computers back home with them and i moved mine and hooked it back up to the internet.


Now i cannot connect two one of my friends even through the internet. We try file transfers and it says i cant connect, and we cannot play online games if one of us is the host

Yeah before you were on your own LAN, now you took the other computers away so they arent part of that LAN anymore. The router (if it was a router and not a hub) will block any outside WAN access to your friends LAN. That is why you cant access. You would have to set up a server and run any processes outside of your friends network - ie the game server or an ftp server to transfer files. So not much you can do right now.

there is no way to reverse this or fix it? cause im not currently on a home network

You would have to set up some sort of server to connect to your friends computer.

Your friend has to look into his router and check the forwards of his ports. It's possible that his router might have resetted back to factory defaults. For example if you want to use PcAnywhere on both of your machines he would have to open ports 5631 and 5632 and add his ip address for those ports in his router. If you need to transfer files to each other you don't need to get a file server. You can do it with remote software or the both of you if you want to can always get FTP-ServU and run it on your machines. Timbukto Pro is another remote software.

If you use a VPN you will have to look into using a dynamic IP, it is a bit trickier than just giving it an IP. I think you have to set up some sort of domain naming otherwise your dynamic IP will keep changing and you will have to manually reset the IP every session or few days. (I am assuming you are not paying for a static IP, like most people.)

As far as hosting a game server you would need to set it up outside of the router, unless there is another way?

but neither of us are using the router anymore lol. We only use the router for that purpose. i dont understand why it cant be fixed really. Neither of us use a router or a firewall that cant be taken down.