Preparation | Create a Static IP | Port Forward | Open Ports | Firewall's | Conclusion

Preparation

I realize that you've probably just arrived at this page, but I'll be sending you away shortly. Why? Before you can connect multiple computers on your LAN to Battle.net, you need to roll up your sleeves and do a little preparation work on your end. The site I would suggest you visit is PortForward.com. It's a well written site, and will be far better at helping you configure the computers on your LAN than I could provide. The PortForward.com site will help you arrive from point A to point B. The goal of this site will be to help you arrive from point B to point C.

At PortForward.com, you will need to accomplish the following tasks:

On your end, you will also need to accomplish the following tasks:

The goal of this site is to help you configure Blizzard Battle.net games

 

Stage 1 - Create a Static IP

The first task you will need to do is create a separate Static IP for each computer. Do not confuse this with how you connect to your ISP. You will most likely have a dynamic IP address with your ISP, which will work fine for what we need to accomplish. Each machine connected to your internet router will need to have it's own static IP address. For example, lets say that Computer 1 will have a static IP of 192.168.123.201. The only number that will vary for each machine on your LAN will be the last octet, in this case, 201. The benefit of creating a static IP on this machine means that until you change something, your machine will always have the same internal address. If you leave your machine with a dynamic address, you will need to update your configuration on a frequent basis. My vote is to do it right the first time, and forget about it.

I've made up a PDF configuration sheet, which will help with setting up your LAN. (download pdf)

Enough of my rambling, click on the following link to configure your computers to use a static IP.
http://www.portforward.com/networking/staticip.htm

 

Stage 2 - Port Forward

At this point, you should have all your computers using a static IP. The next step will be to configure your router to use port forwarding. Besides having a distinct static IP for each computer on your LAN, you will also need to assign a port number to each machine. By default Battle.net uses port 6112. Since each computer needs a distinct port number, we will need to assign individual port numbers to each of your computers. If you use the PDF I created, there will be suggested port numbers defined for each computer.

When you go to http://www.portforward.com/routers.htm, you will need to select your router first, and then you will need to select an appropriate game. I'll suggest that you select StarCraft, but any of the Blizzard Battle.net games should work. The one thing to keep in mind is that you will only want to forward a unique port to each computer on your LAN. If you specify a range of ports 6112-6119, you won't have any ports left to assign to the other computers on your LAN. I will also recommend that you assign the suggested port number listed on the Battle.LAN PDF, not necessarily the number shown at PortForward.com.

For example, Computer 1 with an IP of 192.168.123.201 will be assigned a port number of 6119. Computer 2 will be assigned a port number of 6118. WarCraft, StarCraft, and Diablo can all use the same assigned port number, so you will only need to do this once for each computer on your LAN.

 

Stage 3 - Open Ports

At this point, you may need to configure your router to open any remaining ports not currently being forwarded. This differs from the Port Forwarding that you configured in the previous step. For example, if you have your computer configured to forward port 6119 to your computer, then all traffic on port 6119 will be sent to only your computer. This step differs in that if any of the computer on your LAN need to use another port, then they all have an equal chance of requesting that particular port. For example, the computer on your LAN that hosts the game may need to initially use additional ports that the other computers on your LAN may not require. This is sort of like calling "shotgun" first, when you want to ride in the passenger seat of a friends car. Blizzard recommends that you open ports 6112-6119 in order to play on Battle.net. Diablo 2 also needs port 4000 open, and World of WarCraft needs port 3724 open as well. In my case, I have ports 3724,4000,6112-6115 opened. Since ports 6116 - 6119 have already been assigned to be forwarded to individual computers on my LAN, I have omitted these from the range of opened ports. You may need to open additional ports for some of the battle.net games, but I personally have not needed to open any more ports than those I've listed previously. Any ports that you have already assigned using port forwarding should not be left open for other machines to access. For example, I did not include port 6119 in my list of open ports, since I wanted to insure that only Computer 1 has access to port number 6119. Realistically, you may not need to open any more ports, but if you have trouble hosting a game, this will be a good place to start.

Also note that ports 6881 - 6999 are used for the Blizzard Downloader. This will increase download times for some software updates, demos, videos, etc. Opening these ports may speed download times, but since this is such a wide range of ports, I tend to leave these closed. Your choice.

One other factor to consider is Port Triggering. The purpose of Port Triggering is to only open ports when they are needed. If I were to specify a trigger of 6112 for the range of ports 6112 - 6119, then that range of ports would only open for a set period of time, after I accessed that port. For example, if I launch StarCraft using the default port 6112, then my NAT router knows that it is safe to open this range of ports. This definitely adds some security to your network, but it also has it's drawbacks. It's not uncommon to be in the middle of a long game, only to have your router decide that you must be done playing, and it's time to close all those open ports. End result - Game Over. I would suggest that you do not enter any port triggers if you plan on playing Battle.net games.

Unfortunately, the more ports you have open can increase your risk of outside attacks. While the risk is relatively small, it's still something you should be aware of. The important thing here is to remember not to open any more ports than you need. If you are worried about leaving ports open, I would suggest that you close them when you are not playing any Battle.net games. The easiest way to do this is with a software firewall, since closing these ports on a hardware router requires that you restart your NAT router. Other users on your LAN may not appreciate being booted from internet every time you restart the router. Truth be told, these ports are almost always open on my machine. Of all the things to worry about in the world today, a few open ports are way down the list.

 

Stage 4 - Firewall's

You may also need to open a range of port numbers if you are using a software firewall. My suggestion is that if you have trouble connecting or staying connected, turn off you firewall. If this solves the problem, then quit your game, turn on your firewall, and start investigating your settings. Unfortunately, for this part of the process, your on your own. There are too many firewall programs for me to cover, and I don't think I could stay awake long enough to actually help much. At the very least, I'd never finish this site. Your NAT router should do a much better job of protecting you than a software firewall. The only real reason you would really need a software firewall is if one of the machines on your LAN has already been infected with a virus. Being a Mac user, that's currently not too much of a concern.

If you do choose to use a software firewall, make sure that you have the following ports open.

 

Conclusion

If you made it this far, then you're ready to start configuring the individual Blizzard games to run on Battle.net.

If you're having trouble, then keep reading.

 

1. Do I need to pay more for a Static IP from my Cable/DSL provider?

No. A dynamic IP when connecting to the internet is fine, you only need to assign a static IP to each of the computers on your LAN. This poor analogy is where all my years of watching TV finally pay off. Think of your LAN as a very large cruise ship and you want to have a meal delivered to your room. Even though the boat is often changing its location (dynamic IP), it shouldn't matter where you are in the ocean, as long as the crew (router) running the ship is aware of the ships location. Your only concern is to make sure that the staff knows which room number to deliver the food to you. Think of your cabin number as your computer IP. You may not have trouble getting food delivered the first few nights, but if you keep switching rooms, then you shouldn't be surprised if you start missing some of your meals. If you give your computer a static IP, this is much like telling the crew that you will always be in cabin #219. At this point, it doesn't matter where the ship is located (dynamic IP), only that you will always be staying in cabin #219.
 

 

2. How does Port Forwarding fit in with your pathetic analogy?

By setting up port forwarding, this is similar to telling the crew that anything from a specific list of contacts (port numbers) should be delivered to your cabin #219. At this point, it doesn't matter if you're in your cabin or not. All packages from an approved contact list will be delivered to cabin #219. In this analogy, if a package has your employers name and address on the box, then it should go directly to only you.

 

3. As bad as this has become, how do open ports fit in with this analogy?
 
Imagine this range of open ports as a list of shared contacts. You may order a pizza when you're docked, and your neighbor may order chinese food. As long as nobody orders the same thing, you shouldn't have any problems. If three of you order pizza from the same place, then you may have trouble getting exactly what you ordered.

 

 

contact: battlelan@junkboxoftech.com