Take the 2-minute tour ×  We need to check for the existence of
a SQL server across all domains prior to attempting to connect
to the server. We can loop through the list of servers on the
local domain use SQLDataSourceEnumerator, but that takes a few
seconds to load up and it only gets the local domain. We are
using SQL Server 2005 and 2008 servers as well as .Net 2010. We
don't want to attempt to connect and wait for the 30 second or
more timeout that appears to be standard if the server doesn't
exist.  Any suggestions would be helpful.  share|improve this
question BTW You can specify the connect timeout yourself. – 
Martin Smith Nov 4 '12 at 12:25 Can you PING the server first?
That doesn't guarantee the server has a running/listening
sqlserver instance but can tell you something about the network
path to that server. Keep in mind that wahtever method you use:
it takes time...(there is no instant/guaranteed yes or no out of
the box) –  rene Nov 4 '12 at 12:31 Check this thread on
StackOverflow. maybe it is