I have a straightforward Next/Next installation of Monitor 4.
Base and Web installed on same Server 2008 R2.
All settings default.
The Monitor can connect to the SQL Host.
But it cannot connect to the Instance.
From the Base/Web server I connect using a different domain account.
The domain account is the same for the SQL Host and the SQL Instance though.
I provide credentials.
The SQL Host is OK - monitored.
The SQL Instance on that host is not monitored due to the Unreachable error.
The account I use for connecting to the SQL Instance has the following:
db_datareader on msdb
SQLAgrentRader on msdb
db_ddladmin on tempdb (this is optional but I have added this out of frustration and due to another thread on this forum saying it must be enabled even thoguh the DOC says different)
VIEW ANY DEFINITION on server
VIEW SERVER STATE on server
VIEW DATABASE STATE on specific databases (for testing in the start)
I have not enabled ALTER TRACE or sysadmin (as these are optional)
I have enabled db_reader, db_writer, db_ddladmin on tempdb (as another thread mentions).
From the computer hosting Base/Web server I can connect to the SQL instance using SSMS and see the expected databases etc.
So I can ping and I can use SSMS as expected.
Still SQL Monitor 4 cannot connect to the SQL Instance on the SQL Host it can connect to.