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Port Information for Firewalls, Proxies, and Routers

Who should I contact regarding the configuration of my firewall, proxy, or router?
Blizzard does not support proxies (Internet connection sharing), firewalls, or routers. The settings provided are suggested settings only. However, we do have some suggested settings for BlackICE, ZoneAlarm® Pro, Sygate Personal Firewall Pro, and Windows XP's Internet Connection Firewall.

You may need to contact your ISP or network administrator for assistance if you have opened the correct ports but still cannot connect or get others connected to you.

What do I need to know about ports?
Anytime your computer receives incoming data, it is sent to a "port". Your computer has many ports that can receive data, and different activities will utilize different ports.

How are ports being restricted?
Most proxy servers, firewalls, and other Internet connection sharing methods can restrict port access. Your configuration may be restricting packets from "unknown sources". In this case an "unknown source" would be defined as any IP address that you have not initiated the contact with. Once you contact the IP address, your proxy and/or firewall considers it "safe", or a "known source", since you initiated the contact. When you create a game on Battle.net, other users need to be able to contact you in order to join. In other words, they need to be able to initiate the contact. This becomes the real problem if your connection is restricting them from contacting you.

What ports are required and with what settings?
In order to connect to Battle.net, through your Local Area Network, while allowing others to connect to games you create, make sure you have the following ports setup as described below.

Diablo and Warcraft II Battle.net Edition:


- Allow port 6112-6119 TCP and UDP out and in

Diablo II:


- Allow port 6112 TCP out and allow established sessions in

- Allow port 4000 TCP out (realm games)

- Allow port 4000 TCP out and in (hosting open games only)