disable MTU discovery by default because some routers can break detec…

…tion and connection in result. Remove UseSafeMtu (for this just use MtuOverride).

LiteNetLib/NetConstants.cs

@@ -56,7 +56,7 @@ public static class NetConstants
 
         internal static readonly int[] PossibleMtu =
         {
-            576  - MaxUdpHeaderSize, //minimal (RFC 1191)
+            //576  - MaxUdpHeaderSize minimal (RFC 1191)
             1024,                    //most games standard
             1232 - MaxUdpHeaderSize,
             1460 - MaxUdpHeaderSize, //google cloud
@@ -66,6 +66,7 @@ public static class NetConstants
         };
 
         //Max possible single packet size
+        public static readonly int InitialMtu = PossibleMtu[0];
         public static readonly int MaxPacketSize = PossibleMtu[PossibleMtu.Length - 1];
         public static readonly int MaxUnreliableDataSize = MaxPacketSize - HeaderSize;
 

LiteNetLib/NetManager.cs

@@ -299,9 +299,10 @@ private struct IncomingData
         public int MtuOverride = 0;
 
         /// <summary>
-        /// Sets initial MTU to lowest possible value according to RFC1191 (576 bytes)
+        /// Automatically discovery mtu starting from. Use at own risk because some routers can break MTU detection
+        /// and connection in result
         /// </summary>
-        public bool UseSafeMtu = false;
+        public bool MtuDiscovery = false;
 
         /// <summary>
         /// First peer. Useful for Client mode

LiteNetLib/NetPeer.cs

@@ -287,13 +287,12 @@ internal void FinishEndPointChange(IPEndPoint newEndPoint)
 
         internal void ResetMtu()
         {
-            _finishMtu = false;
+            //finish if discovery disabled
+            _finishMtu = !NetManager.MtuDiscovery;
             if (NetManager.MtuOverride > 0)
                 OverrideMtu(NetManager.MtuOverride);
-            else if (NetManager.UseSafeMtu)
-                SetMtu(0);
             else
-                SetMtu(1);
+                SetMtu(0);
         }
 
         private void SetMtu(int mtuIdx)
@@ -1406,7 +1405,7 @@ internal void Update(float deltaTime)
                     _channelSendQueue.Enqueue(channel);
                 }
             }
-            
+
             if (_unreliablePendingCount > 0)
             {
                 int unreliableCount;