Do not try to connect to ourselves as a peer.

src/MonoTorrent/MonoTorrent.Client/Managers/ConnectionManager.cs

@@ -36,6 +36,7 @@
 using System.Diagnostics;
 using System.Collections.Generic;
 using System.Net;
+using System.Net.NetworkInformation;
 using MonoTorrent.Client.Messages;
 using MonoTorrent.Client.Connections;
 using MonoTorrent.Client.Messages.FastPeer;
@@ -641,7 +642,21 @@ bool TryConnect (TorrentManager manager)
             // Remove the peer from the lists so we can start connecting to him
             peer = manager.Peers.AvailablePeers[i];
             manager.Peers.AvailablePeers.RemoveAt(i);
-
+
+            // Do not try to connect to ourselves
+            if (peer.ConnectionUri.Port == manager.Engine.Listener.Endpoint.Port)
+            {
+                if (manager.Engine.Listener.Endpoint.Address.ToString() == peer.ConnectionUri.Host)
+                    return false;
+
+                if (manager.Engine.Listener.Endpoint.Address == IPAddress.Any)
+                    foreach (var intf in NetworkInterface.GetAllNetworkInterfaces())
+                        if (intf.OperationalStatus == OperationalStatus.Up)
+                            foreach (var ip in intf.GetIPProperties().UnicastAddresses)
+                                if (ip.Address.ToString() == peer.ConnectionUri.Host)
+                                    return false;
+            }
+
             if (ShouldBanPeer(peer))
                 return false;