How do I resolve the "SNMPERR_BAD_SENDTO (SNMP error # -12)" error when adding a sensor for physical disks on a QNAP NAS?
You might have an issue on the remote probe in regards to the outgoing IP here...
https://kb.paessler.com/en/topic/29353-snmperr-bad-sendto-error-snmp-12.
A unique management IP address is definitely a good idea; then you will need a Remote Probe in the network where that IP belongs to.