NPM Network Topoogy Resource

NPM gets this information during the discovery process when you use Network Sonar.  Currently it only collects Layer 2 connection information.  In the upcoming version there have been improvements to this system including the collection of Layer 3 connection information.

If you search Thwack you should find several threads regarding the topology discovery stuff.

Currently, I only have the Network Sonar Discovery configured to scan a handfull of subnets for new devices, volumes and interfaces. It works correctly and every week it discovers any new nodes that are added to the network.

What doesn't make sense is that the Network Topology resource only displays devices connected to one of our Cisco switches. Why would it only discover devices attached to this one switch? Were monitoring hundreds of other Cisco switches in Orion without any similiar topology information. Any ideas?

Is SNMP enabled on all devices?

I have experienced similarly odd behavior where it will collect topology data from one switch but not others as well.  It's possible that this switch is the only one that is providing it information via the MIB's that it uses to collect the topology data.

When I was still trying to get topology discovery to work I did see that switch uplinks also need to be monitored in order for discovery to detect the connection.

I started running a discovery to populate the switch nodes into NPM.
Then I manually added the uplink ports (on all connected switches from that discovery).
Finally I re-rerun the discovery in order to add toplogy.

In the end I just disabled topology discovery on all my discovery jobs because the discovered topology was never complete and it caused many of my discovery jobs to take longer than the 10 hour max timeout.

I'm curious to see how well the v10.2 topology discovery does with multi-layer, dual-connected chassis switches containing a couple hundred VLANs.

Please check this link mentioned below.