title: SQL Server "network-related or instance-specific error" once a day or so (perplexed!)
body: <p>We are experiencing the same error as <a href="https://stackoverflow.com/questions/428846/strange-intermittent-sql-connection-error-fixes-on-reboot-comes-back-after-3-5">this StackOverflow Q</a> ...</p>
  
  <pre><code>System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)
     at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
     at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
     at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
     at System.Data.SqlClient.SqlConnection.Open()
     at System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user)
     at System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe()
     at System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode()
     at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
  </code></pre>
  
  <p>... except that in the referenced StackOverflow Q, they need to restart SQL Server once the error occurs - and we do not. We'll get this error once a day, or once every few days - and all is fine after the error occurs, until the next time it occurs.</p>
  
  <p>This makes us think it's not a "forgot to close connections" issue. We have a moderately busy ASP.NET 4.0 WebForms / SQL Server 2008 R2 app; but we're quite positive we're not exceeding the max # of database connections.</p>
  
  <p>Any thoughts on this problem, or an approach to diagnose?</p>