Detect SQL Server Availability

This C# function helps you check if SQL Server is running fine on a particular server and port. Useful to use on app startup, or for troubleshooting firewall problems after a Windows SP2 installation.

using System.Net;
using System.Net.Sockets;

public bool CheckSQLServer(string SQLHost, int SQLPort)
{
  try
  {
      IPHostEntry IPHost = new IPHostEntry();
      IPHost = Dns.Resolve(SQLHost);

      IPAddress IPAddr = IPHost.AddressList[0];

      TcpClient TcpCli = new TcpClient();
      TcpCli.Connect(IPAddr, SQLPort);
      TcpCli.Close();

      return true;
  }
  catch
  {
      return false;
  }
}