My Monday (and other) early morning routines is to check my 'Problem Nodes' page in Orion to see which nodes are having issues - usually with SNMP.
I find a switch with an error like '.... in an Unknown state' and click on it. I then click on List Resorces which some times will show a list of interfaces - some times I will get an error referncing SNMP.
For example, I just clicked on a switch in the web interface and clicked on List Interfaces and it rattled off the interfaces okay and all looked normal. I then looked in the System Manager and it showed 1 interface as green and the other as a question mark. When I clciked on Show Interface in System Manager I got the error 'SwitchName is currently down, unreachable, or 'SNMPStringHere' is not a valid SNMP community string'.... Perplexed as to why the web will show me one thing while the System Manager shows me something different.
In any case, I then usually have to click on 'Edit SNMP Credentials' in System Manager, make no changes and then click OK. Then I click on 'Validate SNMP' getting a 'Node Validation Successful' then click Apply then List Resources then Poll. I do this for any of the devices that show up on the Problem Node page.
Why do I have to keep doing this? Like I said it is common enough that I have to integrate it into my morning practice.
This happens on 9.1 SP5 and 9.5.1
