snmp on cisco router had been working but suddenly stopped responding...all tunnel interfaces discovered through snmp suddenly grayed out (Unknown State). what could be the issue?
I have had a handful of switches like this over the last year, only fix I know of is a restart f the entire device. If there is a better way I'd love to learn it
'
Can you running smnpwalk and see the time the conversations package, or running wireshk too.
most likely because the ifIndex has changed for the tunnel interfaces. I know it happens on ASA, not sure about routers though. See if your router responds to the cisco cras mib in which case you can set up a custom snmp table poller just for the tunnel interfaces.
Check to see if SNMP still works on the device. Go into 'Edit Properties' for the node and click on the the Test button beneath the Community String settings.
If that works, then the ifindex has changed. You could use the command "snmp-server ifindex persist" to stop them from changing.
If that doesn't work, then make sure SNMP is configured correctly on the device (access list etc) and check to see if there's any firewall blocking SNMP to that device.
