Peer/server discovery

Peer discovery is the process of clients detecting what servers are available. Discovery requests can be made in two ways; locally as a broadcast, which will send a signal to all peers on your subnet. Secondly you can contact an ip address directly and query it if a server is running.

Responding to discovery requests are done in the same way regardless of how the request is made.

Here's how to do on the client side; ie. the side which makes a request:

// Enable DiscoveryResponse messages

config.EnableMessageType(NetIncomingMessageType.DiscoveryResponse);

// Emit a discovery signal

Client.DiscoverLocalPeers(14242);

This will send a discovery signal to your subnet; Here's how to receive the signal on the server side, and send a response back to the client:

// Enable DiscoveryRequest messages

config.EnableMessageType(NetIncomingMessageType.DiscoveryRequest);

// Standard message reading loop

while ((inc = Server.ReadMessage()) != null)

    switch (inc.MessageType)

        case NetIncomingMessageType.DiscoveryRequest:

            // Create a response and write some example data to it

            NetOutgoingMessage response = Server.CreateMessage();

            response.Write("My server name");

            // Send the response to the sender of the request

            Server.SendDiscoveryResponse(response, inc.SenderEndpoint);

            break;

When the response then reaches the client, you can read the data you wrote on the server:

// Standard message reading loop

while ((inc = Client.ReadMessage()) != null)

    switch (inc.MessageType)

        case NetIncomingMessageType.DiscoveryResponse:

            Console.WriteLine("Found server at " + inc.SenderEndpoint + " name: " + inc.ReadString());

            break;