Devices with out-of-scope interfaces

A network might contain devices that are within the discovery scope but that contain interfaces that are out of scope. Because the device is in scope, the default behavior of the layer 3 discovery agents is to download the interface table of the device and discover all the interfaces of a device, even if the interfaces themselves are out of scope.

If this situation applies to your network, and you want to modify the way in which the discovery process handles devices that are partially in scope, there are several ways to modify the discovery and monitoring process to exclude these interfaces from the discovery.

A possible configuration adjustment is to modify the insert into the scope.instantiateFilter such that the out-of-scope interfaces are not instantiated. This solution means that the out-of-scope interfaces are still discovered, but are not passed to MODEL to be instantiated to an Active Object Class (AOC); therefore the out-of-scope interfaces are not represented on the topology or monitored.

You could also configure an SNMP instance filter to prevent the downloading of SNMP data for certain interfaces.

You could also filter the data returned by the discovery agents using the DiscoAgentReturns.filter configuration file.