question

>> Do I need to do anything else on the server side to enable UDP connections?

To interact with PlayFab GSDK, your game server no need to do anything extra to “enable” UDP connections. For your case, you just need to modify the sample from the LiteNetLib official GitHub page to start the server.

Have you tried to follow this doc -- Locally debugging game servers and integration with PlayFab to debug the game server locally? If so, you can navigate to the path of OutputFolder in the MultiplayerSettings to check the PF_ConsoleLogs for error messages. Then you can do troubleshooting according to the logs.

We tried to do a simple interaction with PlayFab GSDK using the modified sample from the LiteNetLib official GitHub page. It can work fine in our testing environment. We use the latest MockVmAgent to test it within the container. You can refer to the following code and follow the Locally debugging game servers and integration with PlayFab to test it.

Besides, if you meet this error, "A fatal error occurred. The required library hostfxr.dll could not be found.", you can follow this thread to select the Self Contained as the Deployment Mode of your sever. We meet this issue about .net core run time in the testing environment. Please ignore it if your sample works fine within the container.

After your server works fine within the container with the MockVmAgent, you can try to deploy it on the PlayFab.

Server sample.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Threading;
using LiteNetLib;
using LiteNetLib.Utils;
using Microsoft.Playfab.Gaming.GSDK.CSharp;
using Newtonsoft.Json;


namespace LitNewLibTestServer
{
    class Program
    {


        private static EventBasedNetListener listener = new EventBasedNetListener();
        private static NetManager server = new NetManager(listener);


        const string ListeningPortKey = "game_port";


        const string AssetFilePath = @"C:\Assets\testassetfile.txt";
        private const string GameCertAlias = "winRunnerTestCert";


        private static List<ConnectedPlayer> players = new List<ConnectedPlayer>();
        private static int requestCount = 0;


        private static bool _isActivated = false;
        private static string _assetFileText = String.Empty;
        private static string _installedCertThumbprint = String.Empty;
        private static DateTimeOffset _nextMaintenance = DateTimeOffset.MinValue;


        static void OnShutdown()
        {
            LogMessage("Shutting down...");


            server.Stop();
            Environment.Exit(0);
        }


        static bool IsHealthy()
        {
            // Should return whether this game server is healthy
            return true;
        }


        static void OnMaintenanceScheduled(DateTimeOffset time)
        {
            LogMessage($"Maintenance Scheduled at: {time}");
            _nextMaintenance = time;
        }


        static void Main(string[] args)
        {


            // GSDK Setup
            try
            {
                GameserverSDK.Start();
            }
            catch (Microsoft.Playfab.Gaming.GSDK.CSharp.GSDKInitializationException initEx)
            {
                LogMessage("Cannot start GSDK. Please make sure the MockAgent is running. ", false);
                LogMessage($"Got Exception: {initEx.ToString()}", false);
                return;
            }
            catch (Exception ex)
            {
                LogMessage($"Got Exception: {ex.ToString()}", false);
            }


            GameserverSDK.RegisterShutdownCallback(OnShutdown);
            GameserverSDK.RegisterHealthCallback(IsHealthy);
            GameserverSDK.RegisterMaintenanceCallback(OnMaintenanceScheduled);


            // Read our asset file
            if (File.Exists(AssetFilePath))
            {
                _assetFileText = File.ReadAllText(AssetFilePath);
            }


            IDictionary<string, string> initialConfig = GameserverSDK.getConfigSettings();


            // Start the http server
            if (initialConfig?.ContainsKey(ListeningPortKey) == true)
            {
                int listeningPort = int.Parse(initialConfig[ListeningPortKey]);


                server.Start(listeningPort /* port */);
            }
            else
            {
                LogMessage($"Cannot find {ListeningPortKey} in GSDK Config Settings. Please make sure the MockAgent is running " +
                           $"and that the MultiplayerSettings.json file includes {ListeningPortKey} as a GamePort Name.");
                return;
            }


            // Load our game certificate if it was installed
            if (initialConfig?.ContainsKey(GameCertAlias) == true)
            {
                string expectedThumbprint = initialConfig[GameCertAlias];
                X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine);
                store.Open(OpenFlags.ReadOnly);
                X509Certificate2Collection certificateCollection = store.Certificates.Find(X509FindType.FindByThumbprint, expectedThumbprint, false);


                if (certificateCollection.Count > 0)
                {
                    _installedCertThumbprint = certificateCollection[0].Thumbprint;
                }
                else
                {
                    LogMessage("Could not find installed game cert in LocalMachine\\My. Expected thumbprint is: " + expectedThumbprint);
                }
            }
            else
            {
                LogMessage("Config did not contain cert! Config is: " + string.Join(";", initialConfig.Select(x => x.Key + "=" + x.Value)));
            }


            Thread t = new Thread(ProcessConnection);
            t.Start();


            if (GameserverSDK.ReadyForPlayers())
            {
                _isActivated = true;


                // After allocation, we can grab the session cookie from the config
                IDictionary<string, string> activeConfig = GameserverSDK.getConfigSettings();


                if (activeConfig.TryGetValue(GameserverSDK.SessionCookieKey, out string sessionCookie))
                {
                    LogMessage($"The session cookie from the allocation call is: {sessionCookie}");
                }
            }
            else
            {
                // No allocation happened, the server is getting terminated (likely because there are too many already in standing by)
                LogMessage("Server is getting terminated.");
            }


        }




        private static void ProcessConnection()
        {
            listener.ConnectionRequestEvent += request =>
            {
                if (server.ConnectedPeersCount < 10 /* max connections */)
                {
                    request.AcceptIfKey("SomeConnectionKey");
                    players.Add(new ConnectedPlayer("gamer" + requestCount));
                    requestCount++;
                    GameserverSDK.UpdateConnectedPlayers(players);
                }


                else
                    request.Reject();
            };


            listener.PeerConnectedEvent += peer =>
            {
                LogMessage(string.Format("We got connection: {0}", peer.EndPoint)); // Show peer ip
                NetDataWriter writer = new NetDataWriter();                 // Create writer class
                writer.Put("Hello client!");                                // Put some string
                peer.Send(writer, DeliveryMethod.ReliableOrdered);          // Send with reliability
            };


            while (true)
            {
                server.PollEvents();
                Thread.Sleep(15);
            }
        }


        private static void LogMessage(string message, bool enableGSDKLogging = true)
        {
            Console.WriteLine(message);
            if (enableGSDKLogging)
            {
                GameserverSDK.LogMessage(message);
            }
        }
    }
}

Client sample.

using LiteNetLib;
using System;
using System.Threading;


namespace LiteNetLibProject
{
    class Program
    {
        static void Main(string[] args)
        {
            EventBasedNetListener listener = new EventBasedNetListener();
            NetManager client = new NetManager(listener);
            client.Start();


//port is the NodePort set in your MultiplayerSettings.json (default 56100)
            client.Connect("localhost" /* host ip or name */, 56100 /* port */, "SomeConnectionKey" /* text key or NetDataWriter */);
            listener.NetworkReceiveEvent += (fromPeer, dataReader, deliveryMethod) =>
            {
                Console.WriteLine("We got: {0}", dataReader.GetString(100 /* max length of string */));
                dataReader.Recycle();
            };


            while (!Console.KeyAvailable)
            {
                client.PollEvents();
                Thread.Sleep(15);
            }


            client.Stop();
        }
    }
}