TcpListener Constructor (IPEndPoint)


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Initializes a new instance of the TcpListener class with the specified local endpoint.

Namespace:   System.Net.Sockets
Assembly:  System (in System.dll)

public TcpListener(
	IPEndPoint localEP


Type: System.Net.IPEndPoint

An IPEndPoint that represents the local endpoint to which to bind the listener Socket.

Exception Condition

localEP is null.

This constructor allows you to specify the local IP address and port number on which to listen for incoming connection attempts. Before using this constructor, you must create an IPEndPoint using the desired local IP address and port number. Pass this IPEndPoint to the constructor as the localEP parameter.

If you do not care which local address is assigned, you can create an IPEndPoint using IPAddress.Any as the address parameter, and the underlying service provider will assign the most appropriate network address. This might help simplify your application if you have multiple network interfaces. If you do not care which local port is used, you can create an IPEndPoint using 0 for the port number. In this case, the service provider will assign an available port number between 1024 and 5000. If you use this approach, you can discover what local network address and port number has been assigned by using the LocalEndpoint property.

Call the Start method to begin listening for incoming connection attempts.


This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.

The following code example creates an instance of the TcpListener class using the local endpoint.

//Creates an instance of the TcpListener class by providing a local endpoint.

IPAddress ipAddress = Dns.Resolve(Dns.GetHostName()).AddressList[0];
IPEndPoint ipLocalEndPoint = new IPEndPoint(ipAddress, 11000); 

    TcpListener tcpListener = new TcpListener(ipLocalEndPoint);
catch ( Exception e ){
    Console.WriteLine( e.ToString());

.NET Framework
Available since 1.1
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