Working script for UDP Broadcast over LAN (to find servers)

I thought to post a script I made that allows to do UDP broadcasting work over LAN. This can help to find servers on a LAN without knowing their IP.

The script itself is designed to search for players and determine which player must start a server. This is because of the particular project I made it for. Anyway, it can easily be adapted to support standard create/join server functionality (see comment in script).

I tried to comment it as good as I can, but if things are unclear, you can post here.

Cheers,
Jordin

 

I found a small, but pretty fatal bug in the script that is fixed now. I recommend everybody who uses this script to download the new version.

 

Thanks for sharing!

 

thank you very much!

 

Sweet awesome sauce of doom. This is fantastic.

 

Good Job. Thanks for sharing.

 

I've got several errors, could someone help me please? I don't understand what's going on.

Code (csharp):

1.  
2. (82,118): error CS0103: The name `scrConnectionManager' does not exist in the current context
3. (82,154): error CS1502: The best overloaded method match for `System.Net.IPEndPoint.IPEndPoint(System.Net.IPAddress, int)' has some invalid arguments
4. (82,154): error CS1503: Argument `#2' cannot convert `object' expression to type `int'
5. (82,26): error CS1502: The best overloaded method match for `System.Net.Sockets.UdpClient.Send(byte[], int, System.Net.IPEndPoint)' has some invalid arguments
6. (82,26): error CS1503: Argument `#3' cannot convert `object' expression to type `System.Net.IPEndPoint'
7. (242,38): error CS0103: The name `scrConnectionManager' does not exist in the current context
8. (242,74): error CS1502: The best overloaded method match for `System.Net.Sockets.UdpClient.UdpClient(System.Net.Sockets.AddressFamily)' has some invalid arguments
9. (242,74): error CS1503: Argument `#1' cannot convert `object' expression to type `System.Net.Sockets.AddressFamily'
10.  

 

I also get these errors, could it be because we are using a newer version of Unity and this script was made over two years ago?

 

probably. by the looks of those errors, it's actually due to the sockets libraries changing. I never saw this script, and am now interested in it, so I might look at it sometime this week.

 

Has anybody been able to port this successfully to Unity 3.4?

 

Here you go.

View attachment $lanbroadcastservice_428.cs

 

Thanks killer, checking it now

 

That only broadcasts on port 22043.

If you want it to broadcast and pickup multiple ports, you will have to use for loops (and I don't feel like it lol).

 

Hey guys,

i'm trying to use the script, but when i receive the callback for Starting a Server, and after i call StartAnnounceBroadCasting(), its says

SocketException: Address already in use
System.Net.Sockets.Socket.Bind (System.Net.EndPoint local_end)
System.Net.Sockets.UdpClient.InitSocket (System.Net.EndPoint localEP)
System.Net.Sockets.UdpClient..ctor (Int32 port)
LANBroadcastService.StartBroadcastingSession () (at Assets/Scripts/Managers/LANBroadcastService.cs:242)​

The line 242 is

objUDPClient = new UdpClient(22043);​

Does anyone have any clues about this issue?

 

Turns out this isn't allowed on a web build. Any ideas how to search for local LAN servers in a web build?

@saulotti: that port is already in use in your machine. try another one.

 

I know it's been a while, but I hope someone can help me.

I am getting this error every time the EndAsyncReceive() is called:

Internal_GetPlayer can only be called from the main thread.
Constructors and field initializers will be executed from the loading thread when loading a scene.

When I comment all references to objSendersIPEndPoint the error stops, so I wonder if it is called from a different thread or something. I really don't know what's going on.

My Unity version is 3.5.6f4.

I appreciate any help

 

The answer to the problem is here http://answers.unity3d.com/questions/175942/error-in-udp-connection-for-multiplayer-tutorial.html

It happens because the code is calling Network.player.ipAddress and it can't because of thread issues. To fix it, add a member variable to the class and in the Start method, assign the value of Network.player.ipAddress (which you can access) into it. Now change the 3 time Network.player.ipAddress is being called and use the member variable instead.

That works for me

 

Due to the sandbox nature of web player from 3.0 and higher it's not possible to do it. Web player games can not be hosted by clients anymore without a proxy to relay messages.
You should either use 2.6.1 or get rid of it.

 

Hi,

I got a problem of calling "StartSearchBroadCasting" function.
What value should I fill in "delJoinServer connectToServer" and "delStartServer startServer"?

Thanks,

 

Unfortunately example does not work.
Due to the fact that not all operations are performed in the threads.

Network.player.ipAddress
Time.time

Cause errors.

 

Bolt, which is on a daily deal 50% sale contains this exact functionality out of the box: https://www.assetstore.unity3d.com/en/#!/content/18358

only 3h left on it.