In the past, our SNMP and SSH sensors sporadically showed a Down status, throwing timeout and authentication errors without any obvious reasons. Suddenly, many sensor types using SNMP and SSH are Down and show these errors. Now the errors do not turn up again. We did not change anything on the target systems like passwords or private keys. The credentials we defined in PRTG are still correct.
What can be the reason for these SNMP and SSH timeouts and auth errors? How can I avoid these SNMP and SSH sensor instabilities?