I'm evaluation Realtime Network Monitor and when I enter public or localhost for the Community string it fails the test. What do I enter?
That screenshot is showing that the machine will only accept SNMP requests from the host 'localhost' using the community string public. That means the machine you are in will only accept SNMP requests from itself (or a host on the network named 'localhost'). For the purpose of getting it up and running the first time, I would recommend choosing the option "Accept SNMP packets from any host" and after verifying that it is working then you can narrow it down to only accept packets from the polling engine host.
The community string must be defined on the device that you are trying to poll. Login to whatever the device is and check on the SNMP settings. My guess is that whatever the device is has SNMP turned off by default. Turn it on and use the default community string (normally public), or change it to something else and then try to poll it from NPM again using that community string.
I did check that. See below
