So i have a 3925 cisco router that is in NPM and has been for years. Today, it reported that the node was down but i could still log into it AND it was still getting netflow and environmental sensors like temp and power readings and full network and internet access. I know when the node is actually down you get the gray box on the red dot for the node, where this time it didn't have the gray box. So i got to looking at the "edit node" page and at the bottom it has the "hardware health MIB" section. i chose the cisco entity sensor MIB and changed polling method to SNMP and it came up.
Orion platform 2015 1.0
no changes to router