cpu

Processor load of a Cisco device, by SNMP

Returns, for each processor of a Cisco switch, router or firewall, its load over the last 5 seconds, minute and 5 minutes, as the device averages them. Two watches are offered: the processor saturated over 5 minutes, and a peak over 1 minute.

How it works

The collector reads cpmCPUTotalTable (CISCO-PROCESS-MIB), one row per processor: a single one on a small switch, one per member of a stack or per module of a chassis.

• A processor is named by the part it sits on, entPhysicalName (ENTITY-MIB), through cpmCPUTotalPhysicalIndex; a processor tied to no part is named by its index (cpu 1). Two of the same name each keep their own, the second carrying its index.
• The loads are cpmCPUTotal5secRev, cpmCPUTotal1minRev and cpmCPUTotal5minRev; an older IOS that serves only cpmCPUTotal5sec, cpmCPUTotal1min and cpmCPUTotal5min is read by those. A load the agent serves in neither form is not returned: never a zero in its place.
• A device that serves no processor stops the collector as misconfigured.

The collector only reads: SNMP sends nothing but reads.

Prerequisites

• The SNMP agent of the device enabled, reachable from the poller (UDP 161), its access restricted to the poller.
• The view granted to the poller includes ciscoProcessMIB (.1.3.6.1.4.1.9.9.109) and entPhysicalName (.1.3.6.1.2.1.47.1.1.1.1.7).
• Read-only access, SNMPv2c or SNMPv3, set on the host or one of its folders (protocol:snmp:* variables).
• Versions: IOS, IOS-XE, NX-OS and the other Cisco systems that serve CISCO-PROCESS-MIB. It stays at the common level of cisco/: the table is the same on all.

Outputs

Watches

Limits

• The load is that of the control plane, the processor that runs the system: traffic switched in hardware does not show in it.
• Which processors and names a given model serves is not verified here without a device.