How can I test a connection to a server with C# given the server's IP address?

Question

How can I programmatically determine if I have access to a server with a given IP address using C#?

Answer 1

Assuming you mean through a TCP socket:

IPAddress IP = new IPAddress();
if(IP.TryParse("127.0.0.1",out IP)){
    Socket s = new Socket(AddressFamily.InterNetwork,
    SocketType.Stream,
    ProtocolType.Tcp);

    try{   
        s.Connect(IPs[0], port);
    }
    catch(Exception ex){
        // something went wrong
    }
}

For more information: http://msdn.microsoft.com/en-us/library/4xzx2d41.aspx?ppud=4

Answer 2

Declare string address and int port and you are ready to connect through the TcpClient class.

System.Net.Sockets.TcpClient client = new TcpClient();
try
{
    client.Connect(address, port);
    Console.WriteLine("Connection open, host active");
} catch (SocketException ex)
{
    Console.WriteLine("Connection could not be established due to: \n" + ex.Message);
}
finally
{
    client.Close();
}

Answer 3

This should do it

bool ssl; ssl = false; int maxWaitMillisec; maxWaitMillisec = 20000; int port = 555;

success = socket.Connect("Your ip address",port,ssl,maxWaitMillisec);

if (success != true) {

MessageBox.Show(socket.LastErrorText);
return;

}

Answer 4

You could use the Ping class (.net 2.0 and above)

    Ping x = new Ping();
    PingReply reply = x.Send(IPAddress.Parse("127.0.0.1"));

    if(reply.Status == IPStatus.Success)
        Console.WriteLine("Address is accessible");

You might want to use the asyunchronous methods in a production system to allow cancelling, etc.