Are you using Service Broker activation by any chance? This would include
also features like SqlDependency or Web pages SqlCacheDependency that are
using activation behind the scenes. Activation can cause the perf counter to
go to abnormaly high values, but is only a perfcounter issue (is not
You can confirm if the connections really grow or is just the a counter
problem by using a management view, like sys.dm_exec_connections.