ENTITY MIB (RFC 4133)
Only the entity physical table (.1.3.6.1.2.1.47.1.1.1) is used/read, that is, no entity logical table (.1.3.6.1.2.1.47.1.2.1) and consequently also no logical to physical mapping table (.1.3.6.1.2.1.47.1.3.1) are inspected. All entities (of interest) are expected to be in the same (default) context. As FOXMAN-UN only supports units and ports, only those layers are being interpreted, all others are ignored.
SNMP PhysicalClass | FOXMAN-UN Types |
|---|---|
other(1) | <none> |
unknown(2) | <none> |
chassis(3) | <none> |
backplane(4) | <none> |
container(5) -- e.g., chassis slot or daughter-card holder | <none> |
powerSupply(6) | unit |
fan(7) | unit |
sensor(8) | <none> |
module(9) -- e.g., plug-in card or daughter-card | unit |
port(10) | port |
stack(11) -- e.g., stack of multiple chassis entities | <none> |
cpu(12) | <none> |
Due to the lack of a representation for all PhysicalClass types, additionally one must be careful when modeling the hardware in order not to create addressing problems. Here is a basic set of rules:
• Down to the slot level only a linear (non-branched) tree can be present (albeit of arbitrary depth); failure to comply with this rule will lead to an empty inventory.
• Units must be modeled inside slots, the slot's parent position field will be taken as the unit's “slot” addressing parameter.
• Ports must be directly attached under units (and only there); their port number is their parent position field (relative to the unit).
Examples of configurations not allowed:
• Two chassis/backplanes with same unit in an NE -> unit addressing clash on NE level.
• Sub-units (daughter cards) having same ports -> port addressing clash on unit level.
A possible configuration looks like this (MIB and FOXMAN-UN in comparison):
The following configuration will not work due to an addressing clash:
The complete table will be read on NE creation, re-establishment of connection and force polling. No «configuration change» notifications are supported.
Please note:
FOXMAN-UN supports as per standard both v2 (RFC 2737) and v3 (RFC 4133) of the ENTITY MIB, as they do not differ in things relevant to FOXMAN-UN.
The following columns from the entPhysicalTable are used in FOXMAN-UN:
SNMP entPhysicalTable column | FOXMAN-UN unit variable |
|---|---|
entPhysicalModelName | cfgName |
parent slot's entPhysicalParentRelPos | slot |
The unit variables «layer» and «subunit» are set fixed to zero (0), «neId» is set accordingly.
SNMP entPhysicalTable column | FOXMAN-UN port variable |
|---|---|
entPhysicalName | label |
entPhysicalModelName | portType |
entPhysicalModelName of parent unit | unitType |
The port variable «isActive» is set fixed to «true», «layerRate» to «unknown», «neId» is set accordingly.
SNMP entPhysicalTable column | FOXMAN-UN port address part |
|---|---|
parent unit's parent slot's entPhysicalParentRelPos (unit's slot) | slot |
entPhysicalParentRelPos | portNumber |
The port address parts «subSlot» and «portTTPId» are set fixed to zero (0).