What makes a device "unreachable"

[Paul Williams]

I have 1400+ devices in LMS, however some of them are listed as "unreachable" - what should I be looking for in terms of making them reachable. I can ping them so they are on the network, its just that LMS says they are unreachable???

[David Stanford]

You should check snmp connectivity to the devices. Do they have snmp ro and rw comm strings? Do the strings on the device(s) match what you have entered for credentials in LMS?

Start with one device and check its snmp connectivity. If snmp is set up and the DCR has the same, then try using the snmpwalk utility in LMS. If it works, then try a packet capture while attempting to discover/add the device.

Is CDP enabled on the device??