title: C#/.NET: FInd out whether a server exists, Query DNS for SVC records
body: <p>Writing a cleint/Server tool I am tasked trying to find a server to connect to. I would love to make things as easy as possible for the user. As such, my idea is to:</p>
  
  <ul>
  <li>CHeck whether specific servers (coded by name) exist (like "mail.xxx" for a mail server, for example - my exampüle is not a mail server;)</li>
  <li>Query otherwise for DNS SVC records, allowing the admin to configure a server location for a specific serivce (that the client connects to).</li>
  </ul>
  
  <p>The result is that the user may have to enter only a domain name, possibly even not even that (using the registered standard domain of the computer in a LAN environment).</p>
  
  <p>Anyone ideas how:</p>
  
  <ul>
  <li>To find out whether a server exists and answers (i.e. is online) in the fastest way? TCP can take a long time if the server is not there. A UDP style ping sounds like a good idea to me. PING itself may be unavailable.</li>
  <li>Anyonw knows how to ask from withint .NET best for a SVC record in a specific (the default) domain?</li>
  </ul>