While using LoadRunner 9.5 for load testing, I am facing an issue; the controller is unable to connect to DB server for monitoring under any category (Windows Resources, SQL Server, etc.). After providing logon credentials, LR throws an error:
Cannot connect to machine <a.b.c.d>
Reason: The network path was not found
(net use failed, error code: 64, error description: The specified network name is no longer available.)

The same was working fine till a day before and I ran a number of tests, but today it stopped working.

1. No configuration changes are made at DB Server, only one patch was deployed creating new indexes in DB.
2. I have tried pinging the machine, response is obtained.
3. The logon credentials used do have administrator privileges.
4. I have deleted the machine and added again, same error message obtained.
5. And lastly, ensured that the machine name entered is correct.

Kindly suggest me what else could be done in order to resolve this issue. Your help would be really appreciated.