How do I play multiplayer on Star Wars : Battlefront 2?

TL;DR: The recommended way to play Star Wars Battlefront II online is a community-project called SWBFSpy. Read the section below called SWBFSpy. If you have the Steam/GoG version read also the section Steam/GoG official online multiplayer.

There are a number of possible ways to still play the original Star Wars Battlefront II online. This holds for the Steam and GoG version of the game as well as the retail version (bought as a CD/DVD).
Besides the alternatives discussed below there is also the official re-enabled online multiplayer exclusively for the Steam/GoG version, which however suffers from some problems (also explained later).

SWBFSpy

SWBFSpy is a community project to re-create online multiplayer (by making available an alternative master server, which is the essential part that makes online multiplayer work; see section Technical details if you are interested). It has the main advantage that it integrates smoothly with the game, i.e. online multiplayer works how it worked before and you do not need an additional third-party program or make an account somewhere.
Note that if you own the Steam/GoG version you are replacing the current online-functionality (see section Steam/GoG official online multiplayer) with SWBFSpy.

Additional information beyond the instructions given below (e.g. for Star Wars Battlefront (not II) or for the PlayStation 2 version of the game) can be found here on SWBFGamers.com.

The easiest way to get SWBFSpy is by downloading the changed executable file from their website and replace your existing file with it. After doing this you are able to play online using SWBFSpy without any extra steps required. If you are uncomfortable with downloading an executable file and you are familiar with hex-editing you can make the necessary changes to your executable file yourself (explained later).

Download instructions

Go to the download website of SWBFSpy, scroll down to the headline Star Wars Battlefront 2 Patches (PC) and click on Click Here To Download for the correct file. Which one this is depends on which version of Star Wars Battlefront II you own:
If you have the retail version (on CD/DVD), you want to get the file named English File (No Registration Needed). If you have the game on Steam or GoG make sure to get the download named STEAM PATCH (No Registration Needed).
You will get forwarded to another website where you can start the download by clicking on the file.

Installation instructions

After the download has finished find the file in your download folder and extract the ZIP file by right-clicking on it, select Extract all... and click the Extract button. A folder will open up. If you see a folder called GameData, open it (only Steam/GoG version). Here you have to copy all files: select all files, right-click on one of them and select Copy.
The further steps are now different depending on the version of the game that you own:

• retail version (CD/DVD):
  Go to your game folder which normally is located at C:\Program Files (x86)\LucasArts\Star Wars Battlefront II. Open the folder GameData and paste the copied files here by right-clicking on a free space and selecting Paste. Right-click on the file BattlefrontII - SWBFSpy.exe and select Send to and Desktop (create shortcut).
  You will have a shortcut on your desktop now which you can open to start the game with SWBFSpy enabled.

• Steam/GoG version:
  Go to your game folder which normally is located at C:\Program Files (x86)\Steam\steamapps\common\Star Wars Battlefront II (it may be different for the GoG version) and open the folder GameData. Here you will now rename a few files now to make sure you don't overwrite your game files but have a copy of them in order to revert the changes at any time later.
  Right-click on the file BattlefrontII.exe, select Rename and enter some new name for it, e.g. BattlefrontII-original.exe (the part .exe may not be visible to you which isn't a problem - just leave it out). Then enter the folder data and _lvl_pc and find the two files shell.lvl and ingame.lvl. Rename those two files as well like before. Now go back two folders until you are where you were before when you renamed your BattlefrontII.exe file. Copy the files from the download to here by right-click on a free space and selecting Paste. You will be asked to merge folders two times, confirm this both times. As a last step select the file called BattlefrontII - SWBFSpy.exe and rename it to (this time the name is important) BattlefrontII.exe (if you don't see a .exe ignore it again - don't add it!).
  If you now start Star Wars Battlefront II the way you always do you will have SWBFSpy enabled.

Nothing further is required to use SWBFSpy. If you go to MULTIPLAYER in the game, just select JOIN or CREATE to join or create a server. (Ignore the tab called GAMESPY and the login form it displays.)
If you only see a handful of servers, make sure that the option to seach all regions is checked: Go to OPTIONS and then ONLINE and activate the setting Search all regions.

Manual (hex-edit) installation instruction

If you do not feel comfortable with downloading an executable file and you feel more comfortable hex-editing your executable file yourself, you can do this instead. Hex-editing means using a hex editor to change your file so that it points to the correct master server address. If you do not know what this means you can just download the file as instructed above.

By hex-editing the file yourself you can replace all occurrences of gamespy DNS addresses by the corresponding ones calling to swbfspy.com, therefore pointing to the new master server. You have to change the following strings in the main executable BattlefrontII.exe by replacing gamespy with swbfspy:

%s.available.gamespy.com  -->  %s.available.swbfspy.com
%s.master.gamespy.com     -->  %s.master.swbfspy.com
%s.ms%d.gamespy.com       -->  %s.ms%d.swbfspy.com
gamestats.gamespy.com     -->  gamestats.swbfspy.com
gpcm.gamespy.com          -->  gpcm.swbfspy.com
gpsp.gamespy.com          -->  gpsp.swbfspy.com
natneg2.gamespy.com       -->  natneg2.swbfspy.com
natneg1.gamespy.com       -->  natneg1.swbfspy.com
motd.gamespy.com/motd/vercheck.asp?productid=%d&versionuniqueid=%s&distid=%d&gamename=%s                    -->  motd.swbfspy.com/motd/vercheck.asp?productid=%d&versionuniqueid=%s&distid=%d&gamename=%s
motd.gamespy.com/motd/motd.asp?userid=%d&productid=%d&versionuniqueid=%s&distid=%d&uniqueid=%s&gamename=%s  -->  motd.swbfspy.com/motd/motd.asp?userid=%d&productid=%d&versionuniqueid=%s&distid=%d&uniqueid=%s&gamename=%s

This will work for the retail (CD/DVD) version or the Steam/GoG version without the new multiplayer update, however it will not work for the Steam/GoG version with the newest update.

GameRanger

Apart from SWBFSpy, GameRanger is another alternative for Star Wars Battlefront II online multiplayer. GameRanger is a program that provides game server lists and social features for a variety of games including Star Wars Battlefront II (and I). I do not know whether GameRanger works with the Steam or GoG version as well as with the retail (CD/DVD) version.

To use GameRanger download it from their website and run the downloaded setup file. You will have to create a free account after installation.
After installing you can see all game servers and can use filters to display only the ones you are interested in. Double-clicking on a server will load up the game automatically and join this server. If you leave a server again you have to close the game entirely (the in-game multiplayer browser will not display anything) and use the GameRanger application to find another server.

Note that GameRanger displays advertisements and offers payed premium accounts. However sometimes it may prove useful to have GameRanger installed so that you can check there for active servers if no one is active at the moment on SWBFSpy.

Tunngle - discontinued

Tunngle uses the LAN connectivity (for within a small home network) of games for online play by adding your computer to a VPN, which can be thought of as an emulated LAN connection over the internet. This technique allows basically every game that comes with LAN connectivity support to be playable over the internet, including Star Wars Battlefront II (and I).

To use Tunngle you have to download the client from their website and create a free account. Upon installation Tunngle will install a virtual network adapter on your computer which may interfere with other VPN connections if you use those.
Once inside the software you can join the lobby for Star Wars Battlefront II and join or create games.

Note that Tunnge displays advertisements and offers payed premium accounts. I cannot tell anything about the amount of player activity on Tunngle.

Steam/GoG official online multiplayer

In October 2017 the online multiplayer functionality has been re-enabled for the Steam and GoG versions of the game. This does not apply to the retail (on CD/DVD) version of the game, so it is listed as the last option in this list. However, if you own the Steam or GoG version this option may be the most preferable of all of them (though you could give SWBFSpy a try nonetheless to see for yourself).

If your game received the latest updates through Steam or the appropriate GoG launcher you can use this new online multiplayer right away. It works the same way like multiplayer worked before.
If you installed SWBFSpy previously you will need to disable it again by following the installation instructions for SWBFSpy above in reverse: delete the current (SWBFSpy) files BattlefrontII.exe, shell.lvl and ingame.lvl and rename the original copies of those files that you created when installing SWBFSpy to the name of the files you just deleted.

In comparison to SWBFSpy this new online multiplayer currently has the disadvantage that it is less stable and the connection quality is generally poorer, resulting in more lag during the game. Additionally there are no dedicated servers (yet) available, which means that all hosted servers are privately hosted. This has the afore-mentioned consequences of laggy and unstable game play (due to servers being hosted on private computers and through private internet connections).
However if gameplay turns out fine for you, you may prefer this option to SWBFSpy as there is generally a higher activity of players than on SWBFSpy.

If you want to use the Steam/GoG-only online multiplayer and SWBFSpy concurrently (e.g. to also play with people that do not own the Steam/GoG version), you have to either switch the three game files back and forth (by renaming or moving them). Alternatively you can create a copy of your entire GameData folder and only switch between those folders which requires only one renaming every time you want to switch.

Hosting servers

If you want to host your own private game this is possible with all above alternatives in a similar fashion as joining a server. Hosting a dedicated server that gives you more control is possible for SWBFSpy and in some way probably for GameRanger and Tunngle (I do no have any detailed information about those). For the Steam/GoG version hosting dedicated servers is currently not possible.

To host a dedicated server using SWBFSpy download the server patch from the same website where you download the files for the normal game. Replacing the appropriate files in the server software (which you have to install beforehand) will create your server on SWBFSpy.

Technical details

For those interested, here is some further technical information about Star Wars Battlefront II online multiplayer.

In June 2014 GameSpy shut down all its online services, which included online multiplayer support for Star Wars Battlefront II (and I). As GameSpy provided the master servers that are responsible for letting the clients (the people that play the game, i.e. you) know which game servers are currently available and how to connect to them, but also to manage security features to make sure product codes are unique for every player, multiplayer for Star Wars Battlefront I and II and many other games was at first no longer possible in the form like it was before.

The reason for that are not missing game servers, which you could host on your computer yourself (and of which still quite a lot are running and online), but the lack of the master servers, that act as the link between the game servers and the clients. Unfortunately, for Star Wars Battlefront II there is no option to directly connect to a game server without the master server available, as a product code verification is required.

There are basically two ways of coping with this situation.

• re-creating the master server to restore multiplayer like it used to work
• using the LAN feature to get the game to connect to a game server without product code verification (which would fail due to the lack of the master server)

Several services provide one of the above solutions. There are projects that aim towards the re-creation of the GameSpy master server - or more so a mock-up of it - and there are programs that use the second way, that work for Star Wars Battlefront II as well as for other games.
GameRanger and Tunngle exploit the LAN connectivity of the game and are generally usable. SWBFSpy is a master server re-creation and is tailored specifically to Star Wars Battlefront I and II (even though other community projects may exist for games that share a similar fate).

SWBFSpy is the direct successor to GameMaster which was essentially the same thing run by the people who developed the technique to create the master server mock-up in the first place. There was also a project called FreeGST, but it was cancelled in favor of the fully functional and more popular GameMaster project.
The changes to game files (and game server files) for SWBFSpy are simply a change of all gamespy.com DNS addresses to swbfspy.com, where the master server mock-up was set up to listen and respond to all client and game server requests in the same way the original master server did. Because of this SWBFSpy has the advantage of being fully integrated into the game and not requiring any third-party application.

GameRanger supports Star Wars Battlefront II as of June 4, 2014

http://www.gameranger.com/news/

When I had a PS2 I'm sure I could host mini games of up to 4 players.

Also, you say you have LAN servers which means you have downloaded the necessary software. I think you are close to being a public host yourself but your will need to get your router to direct traffic from the rest of your internet to your pc hosting the server software.

If you google on port-forwarding you may get some joy.

In fact to start you off try this... http://www.swbfgamers.com/index.php?topic=51.0