I've enabled the public (read-only) SNMP scanning in LS 5.
I've noticed a few PC's that are on switch port X which is connected to a non-managed switch downstream are not showing up, while others are.
These two devices are on managed switch port 30, with a desktop switch in the room with the devices.
GigabitEthernet1/0/30 PC 1
GigabitEthernet1/0/30 Printer 1
This managed switch port, 35, has a non-managed switch connected to port 35, but doesn't show the devices in LS Network Interfaces column
GigabitEthernet1/0/35
Shows Down, but devices which I know are on this port via non-managed switch are active and respond to PING.
In fact, when I first scanned, two of the devices showed up under the switch page in LS, but when I rescanned, they disappeared. I'm remoted into one of them, so they are clearly active.