NPM automatically picks up all available interfaces when you add a node and then you choose when ones you want to monitor. Run a discovery or hit list resources on the node details of an xisting node and you will see loopbacks wherever they exist.
Do you mean switching loops like when STP isn't working correctly?
It's just for those switches that are basic that don't have STP, and how can I create a dashboard for looking that there is or there are loopback(s)?
Couple of ways, it may depend on what you are looking to do with the interfaces.
A report for Interfaces, using the GUI
Create a Custom Table Report; Report on Interfaces
Setup something like this; if you have different loopback names you may want each specific iteration so you do not pick up on other interfaces with LO in the name, that may not be loopbacks. I suppose it could happen
If you want to delete these interfaces, use the Manage Nodes Page, change the search to Interface and search for loopback, lo, et al.
Select and then delete as desired.
Loop1 Systems: SolarWinds Training and Professional Services
The term you are looking for is switching loop, not a loopback. Loopback is a type of logical interface, switching loop is when there are more than 1 layer 2 paths to a device which tends to contribute to packet storms. To be honest I've never had to track switching loops with Solarwinds, I expect you might see traffic pick up across every switch interface tied to a specific VLAN, but I've not seen what the metrics look like when one is happening so I could only speculate about how to show that in a dashboard. You could try something like create a table showing the avg percent utilization for all interfaces using each vlanid
I just whipped this report up and maybe it would be useful, maybe not. Uses custom table resource, datasource is any interface with vlan id info (if your switches don't have STP honestly they might not be reporting this kind of stuff so I'd do some validation if it was you)
For my columns I just chose the name of the vlanid, and then added in the total percent utilization, rx and tx, then make sure to set data aggregation to average for all 3 of those metrics.
You could also take that same kind of information and make it into a chart to see the change over time.
I would expect that if you had a broadcast storm you would see utilization pick up, although im not sure if broadcast storms normally cause interface utilization to spike or maybe it would just be packets per second. In any case hopefully that gives you some leads on things you could try to look for.