TcpClient.Connect Method (IPAddress[], Int32)

Connects the client to a remote TCP host using the specified IP addresses and port number.

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

public void Connect (
	IPAddress[] ipAddresses,
	int port
public void Connect (
	IPAddress[] ipAddresses, 
	int port
public function Connect (
	ipAddresses : IPAddress[], 
	port : int
Not applicable.



The IPAddress array of the host to which you intend to connect.


The port number to which you intend to connect.

Exception typeCondition


The ipAddresses parameter is a null reference (Nothing in Visual Basic).


The port number is not valid.


An error occurred when attempting to access the socket. See the Remarks section for more information.


The Socket has been closed.


A caller higher in the call stack does not have permission for the requested operation.


This method is valid for sockets that use the InterNetwork flag or the InterNetworkV6 flag.

This method is typically used immediately after a call to the BeginGetHostAddresses method, which can return multiple IP addresses for a single host. Call the Connect method to establish a synchronous remote host connection to the host specified by the array of IPAddress elements and the port number. The Connect method will block until it either connects or fails. After connecting with the remote host, use the GetStream method to obtain the underlying NetworkStream. Use this NetworkStream to send and receive data.


If you receive a SocketException, use SocketException.ErrorCode to obtain the specific error code. After you have obtained this code, you can refer to the Windows Sockets version 2 API error code documentation in the MSDN library at for a detailed description of the error.


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

The following code example uses an IP Address and port number to connect with a remote host.

static void DoConnect(string host, int port)
    // Connect to the specified host.
    TcpClient t = new TcpClient(AddressFamily.InterNetwork);
    IPAddress[] IPAddresses = Dns.GetHostAddresses(host);

    Console.WriteLine("Establishing connection to {0}", host);
    t.Connect(IPAddresses, port);

    Console.WriteLine("Connection established");

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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