We have a single core PRTG server with several remote probes installed on servers behind routers and firewalls on separate subnets.. We have around 700 sensors all working fine (monitoring things like SQL databases, services, server memory & HDD space etc) but when I add SNMP sensors they always fail to connect.
If I add SNMP sensors to devices on the same network as the core server everything works as it should do.
My question is that, even with a remote probe installed on a remote server, do I need to open port 161 (and 162?) on the firewall to allow SNMP communication with the core server?
Many thanks, Mark