<p>How can I <em>programmatically</em> determine if I have access to a server (TCP) with a given IP address and port using C#?</p>

Assuming you mean through a TCP socket:
```
```
IPAddress IP;
if(IPAddress.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