Provider=VIRTOLEDB;Data Source=server1:port1,server2:port2,server3;User Id=dba;Password=dba;Initial Catalog=Demo;Prompt=NoPrompt;
  Provider=VIRTOLEDB;Data Source=server1:port1,server2:port2,server3;User Id=dba;
Password=dba;Initial Catalog=Demo;Prompt=NoPrompt;Round Robin=true