SQL Server不存在或访问被拒绝(间歇性地)

I use a Microsoft Access 2010 front end with linked tables on an SQL Server 2012 installation. Local network. When Access Starts, a VBA script runs which connects to the SQL server and performs some checks. I recently upgraded from SQL Server 2008 to 2012, that's when the connection between client and Server started to fail intermittently.I use a Microsoft Access 2010 front end with li