Porten Forwarden voor Games

Aliens vs. Predator
(Watch Out! Opens a wide port range!)
IN    UDP  80
IN    UDP  2300 - 2400
IN    UDP  8000 - 8999

Anarchy Online (BETA)
IN    TCP 7013
IN    TCP 7500 - 7501
IN    UDP 7013
IN    UDP 7500 - 7501

Asheron's Call [support page] [mapping info]
OUT    UDP  9000, 9004, 9008, 9012
IN    UDP  9000, 9001, 9004, 9005, 9012, 9013
NOTE! You may also need to open the MSN Game Zone and DX ports 

Black and White
IN    TCP     2611 - 2612
IN    TCP     6667
IN    UDP    6500
IN    UDP    27900

Blizzard Battlenet
This allows for -1- machine on the network to take advantage of 
Blizzard's BattleNet system for playing online games such as Diablo II and StarCraft. 
The 6112 port is needed in both TCP and UDP for StarCraft and Diablo II, and the 4000 port is needed for Diablo II. 
No other settings should be needed.
IN    TCP     4000
IN    TCP     6112
IN    UDP    6112

Bungie.net, Myth, Myth II Server
IN    TCP     3453

Dark Reign 2
IN    TCP     26214
IN    UDP     26214

Delta Force (Client and Server)
OUT     UDP     3568
IN      TCP     3100    3999
OUT     TCP     3100    3999
IN      UDP     3100    3999
OUT     UDP     3100    3999

Delta Force 2
IN      UDP  3568
IN      UDP  3569

Elite Force
IN    UDP     26000
IN    UDP     27500
IN    UDP     27910
IN    UDP     27960
NOTE: If the server is behind the same router/firewall as other clients, then all of the clients 
will have to add "+set net_port 27961," "27962," etc. to their shortcut command lines.  
Otherwise, they will not be able to use the in-game internet game browser. 
This is due to the fact that EF uses the same port (27960) for both the client and the server.

Everquest
(Watch Out! Opens a wide port range!)
See this Everquest page for more info
IN   TCP   1024  7000
IN   UDP  1024  6000
Note: May have to open this last UDP range even wider

F-16, Mig 29
IN    UDP    3862
IN    UDP    3863

F-22 Lightning 3
(Watch Out! Opens a wide port range!)
IN    UDP     3875
IN    UDP     4533
IN    UDP     4534
IN    UDP     4660 - 4670 (for VON)

F-22 Raptor
IN    UDP    3874, 3875

Fighter Ace II
(Watch Out! Opens a wide port range!)
IN    TCP     50000 - 50100
IN    UDP    50000 - 50100

for DX play also open these ports:
IN    TCP     47624
IN    TCP     2300 - 2400
IN    UDP     2300 - 2400

Half Life
IN    UDP  6003
IN    UDP  7002
IN    UDP  27010
IN    UDP  27015
IN    UDP  27025

Half Life Server
IN    UDP  27015

Heretic II Server
IN    TCP     28910

Hexen II
Each computer hosting Hexen II must use a different port number, 
starting at 26900 and incrementing by 1.

IN    UDP     26900 (for first player)

KALI
Each computer using KALI must use a different port number, starting at 2213 and incrementing by 1.

IN    UDP     2213 (for first player)
IN    UDP     6666

Kohan Immortal Sovereigns
This allows you to host a Kohan game and have it show
up on Gamespy, otherwise no one will be able to see your
game outside of your lan. Only the ICS server can host 
games and have them show up however.
IN    UDP     3855
IN    UDP     17437
IN    TCP      3855
IN    TCP      17437

Motorhead server
IN    UDP     16000
IN    TCP      16000
IN    TCP      16010 - 16030
IN    UDP     16010 - 16030

The ports 16010-16030 are ports I specified in the 
MotorHead dedicated server client ports section. 
You need to specify client ports so that Motorhead 
does not assign client ports randomly.

MSN Game Zone [support page] [DX support page]
(Watch Out! Opens a wide port range!)
IN    TCP     6667
IN    TCP     28800 - 29000

for DX play also open these ports:
IN    TCP     47624
IN    TCP     2300 - 2400
IN    UDP     2300 - 2400

Need for Speed - Porche
IN    UDP     9442

Need for Speed 3- Hot Pursuit
IN    TCP  1030

Operation FlashPoint

TCP 47624 ~ 47624
TCP 2234 ~ 2234
BOTH 6073 ~ 6073

Outlaws
IN    UDP     5310
IN    TCP      5310

Quake2  (Client and Server)
IN    UDP     27910

QuakeIII  
Each computer playing QuakeIII must use a different port number, 
starting at 27660 and incrementing by 1.
 You'll also need to do the following:

1. Right click on the QIII icon 
2. Choose "Properties" 
3. In the Target field you'll see a line like "C:\Program Files\Quake III Arena\quake3.exe" 
4. Add the Quake III net_port command to specify a unique communication port for each system.
 The complete field should look like this: "C:\Program Files\Quake III Arena\quake3.exe" +set net_port 27660 
5. Click OK. 
6. Repeat for each system behind the NAT, adding one to the net_port selected (27660,27661,27662)

IN    UDP     27660  (for first player)

Rainbow Six (Client and Server)
OUT     TCP     2346
IN      TCP     2346

Rogue Spear
OUT     TCP     2346
IN      TCP     2346

Soldier of Fortune
IN   UDP   28910 - 28915

Starcraft
IN   UDP   6112

Starfleet Command
(Watch Out! Opens a wide port range!)
IN   TCP  2300 - 2400
IN   TCP  47624
IN   UDP 2300 - 2400
IN   UDP 47624

SWAT3
IN   TCP 16639
IN   UDP 16638

Ultima
IN   TCP   5001-5010 Game
IN   TCP   7775-7777 Login 
IN   TCP   8888 Patch 
IN   TCP   8800-8900 UO Messenger 
IN   TCP   9999 Patch
IN   TCP   7875 UOMonitor

Port 7875 is not used by the game, but by UOMonitor,
 which many players use to monitor server status.

Unreal  Tournament server
IN    UDP 7777 (default gameplay port)
IN    UDP 7778 (server query port
IN    UDP 7779+ (UDP 7779+ are allocated dynamically for each
                        helper UdpLink objects, including UdpServerUplin
                        objects. Try starting with 7779-7781 and add
                        ports if needed.))
IN    UDP 27900 (server query, if master server uplink is enabled.
                         Some master servers use other ports, like 27500)
IN    TCP 8080  
(Port 8080 is for UT Server Admin. In the [UWeb.WebServer] section of the server.ini file, 
set the ListenPort to 8080 (to match the mapped port above) 
and ServerName to the IP assigned to the router from your ISP.)

Westwood Online - C&C Tiberian Sun & Dune 2000
Note: Westwood Online supports only one user per public IP address at any given time. 
Apprule courtesy of Quantus' World
OUT     TCP     4000
IN      TCP     4000
IN      UDP     1140    1234
IN      TCP     1140    1234
OUT     UDP     1140    1234
OUT     TCP     1140    1234 

ZNES
IN    UDP  7845 [Use Quake Translation if you can set it]