The term module containment refers to the process of associating a separately managed routing module to the switch chassis in which that module is contained. Module containment must be inferred for a switch that has a removable module (for example, MSFC, RSFC, RSM, and FWSM) that is contained within the switch chassis but is separately managed.

When the module is separately managed from its switch chassis, the two have different CLI data files (such as .cfg and .cdp), MIB data, and so on, and are imported into the NetIM database as two separate devices. To accurately represent the two separately managed components as a single device rather than two separate devices, Layer 3 module containment must be inferred.

For the data from the switch and its module to be associated and merged into a single device upon import into analysis software, the two devices must be associated in NetIM. This module containment process is performed by the Link and Connection Inference adapter. After the Link and Connection Inference adapter runs, the Chassis Module Summary reports the module containment relationships inferred by the Module Containment engine.

The Module Containment Engine is enabled by default. If your network does not contain any switch chassis devices with separately managed modules, you can disable this engine without impacting the fidelity of the resulting network topology database. If you are not sure, you should leave this engine enabled.

Module containment can be inferred by correlating the serial number for the routing module to one of the modules in the switch chassis. This is the primary method of inferring module containment.

The following data is required to infer module containment based on serial number:

Some Cisco RSM modules do not report serial number in device version output; therefore module containment based on serial number is unsuccessful for these devices. However both the switch and the RSM module may report a shared MAC address. The module containment engine attempts to identify a containment relationship based on the duplication of a MAC address on an RSM and a switch chassis. When the same MAC address is reflected for the vlan0 interface on a routing module and an interface in a switch chassis, the module containment engine infers that the routing module is contained in that switch chassis. This method is used to infer module containment only for Cisco RSM cards.

The NetIM database must contain needed data for both the switch chassis and the routing module card in order for a hybrid mode routing switch to be correctly represented. If either the switch chassis or the module card is missing from the NetIM database or if the data required to infer the relationship is missing, the resulting inferred topology will not be correctly represented. To determine if a module card or switch chassis is missing from NetIM or if data needed to infer the relationship is missing, consult the following reports

When consulting these reports, keep in mind that they will only contain useful information after you run the Link and Connection Inference adapter.