Active Scanning is a new feature in PeakHour that can scan your local network for SNMP devices that can be monitored.
SNMP itself does not support automatic discovery (unlike UPnP) and it can often be difficult or time-consuming to figure out the IP addresses of all the potential devices on your network.
Active Scanning will do a single-pass scan of all of the IP addresses in the local subnet of your active network interface of your Mac. It uses SNMPv1/2c and the default SNMP community string of public.
Devices that use SNMPv3 or have a community other that public will not be automatically found by Active Scanning.
Active Scanning can appear as suspicious activity if your network is actively monitored. It is recommended that you do not use Active Scanning on corporate networks, public WiFi or other networks that you do not own as it may trigger a security alert.