Common errors in DPA

Would like some guidance on what to tell database owners when I get theses errors.

failed to start due to [IO Error: The Network Adapter could not establish the connection].

failed to start due to [I/O Error: DB server closed connection.]. 

failed to start due to [Login timed out.].

For the two below, this is happening on multple instances. 

failed in job [QuickPollJob] due to [I/O Error: Connection reset]. Will attempt to retry every [480] seconds...

No listener is present for database ID [74]. The listener needs to have the same host (IP or DNS) and port as the monitored instance.