How to fix this SocketException

Question

I have a loop that opens a socket, acts on the socket, then closes the socket and restarts. However, on the second iteration I get SocketException, Only one usage of each socket address (protocol/network address/port) is normally permitted.
However, the socket should be closed, netstat -a doesn't show that I'm listening on that port or anything. The code that throws the exception is:

_bindedLocalSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
_bindedLocalSocket.Bind(new IPEndPoint(Util.ChannelProfileToListeningAddress(_profile), _profile.ListenPort));
_bindedLocalSocket.Listen(30);
_bindedLocalSocket.BeginAccept(new AsyncCallback(OnRequested), null);

However, I think the culprit is not that code, just before I get to that code, and before I try to close the connection I get this:

An existing connection was forcibly closed by the remote host
   at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
   at Poderosa.PortForwarding.SynchronizedSocket.EndReceive(IAsyncResult ar)
   at Poderosa.PortForwarding.Channel.OnSocketData(IAsyncResult result)

Once I close the program and run it again, it can make the first connection fine, the second one acts just the same (SocketException). Does anybody have any idea how I can fix this?

Answer 1

It's a known issue on windows, that even if you've closed a socket, there is a waittime before the resource is released back to the OS.

There is a way to manually set the waittime for a socket in .NET, however it may be a better option to revisit your design, to instead keep the listener socket open, instead of closing it down, and instead close the new socket that is created during Socket.Accept();

Answer 2

I thought that socket.Close() took care of that, but I guess not. In that case, you need to use:

socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);

You can read more about socket options here.