ServiceNow uses SNMP (Simple Network Management Protocol) data and CDP (Cisco Discovery Protocol) to gather the data that each device reports about itself. However, this approach has a two key limitations:
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It doesn’t reliably map L2–L3 topologies.
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It only discovers certain vendors.
With these limitations, it’s not uncommon to see CMDBs that are wrong about 20-40% of the network.
However, IP Fabric takes a different approach that fills the gaps in ServiceNow’s discovery. It reads device data via API and CLI (Command Line Interface), and then hops from device to device until 100% of your network is found. The end result is an interactive, vendor-neutral model of L1–L3 topologies, which represent your actual network behavior across vendors, from core to cloud to edge. This model can be used to validate your ServiceNow CMDB, and to surface any places where your CMDB drifts from network reality.