banshee/network-collection/network/cisco/snmp/memory

Memory pools of a Cisco device, by SNMP

Returns, for each memory pool of a Cisco device (Processor, I/O…), the memory used and free and the share used, and which MIB was read. Two watches are offered: the memory saturated, and little free memory.

Versions

IOS, IOS-XE, NX-OS and the other Cisco systems that serve one of the two MIBs. It stays at the common level of cisco/: it reads whichever one the device serves.

How it works

CISCO-ENHANCED-MEMPOOL-MIB is read first, cempMemPoolTable: one row per pool and per part (each member of a stack, each module). Its 64-bit counters, cempMemPoolHCUsed and cempMemPoolHCFree, are read when the agent serves them, otherwise the 32-bit cempMemPoolUsed and cempMemPoolFree.
CISCO-MEMORY-POOL-MIB, ciscoMemoryPoolTable, is read when the agent serves no enhanced pool: the older devices.
The source output says which one was read: cisco-enhanced-mempool-mib or cisco-memory-pool-mib.
Only the pools the agent marks valid are returned. A pool is named by the name the device gives it; two pools of the same name (one per member of a stack) each keep their own, the second carrying its index.
A device that serves no valid pool 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 ciscoEnhancedMemPoolMIB (.1.3.6.1.4.1.9.9.221) or ciscoMemoryPoolMIB (.1.3.6.1.4.1.9.9.48).
Read-only access, SNMPv2c or SNMPv3, set on the host or one of its folders (protocol:snmp:* variables).

Outputs

Name	Label	Unit	Per instance
`used-percent`	Used memory	%	yes, per pool
`used`	Used memory	MiB	yes, per pool
`free`	Free memory	MiB	yes, per pool
`source`	MIB read	—	no

Watches

Name	Title	Kind	Defaults	Checked by default
`memory-high`	Memory saturated	above a threshold, on `used-percent`	warning above 80 %, critical above 90 %, for 3 runs	yes
`free`	Little free memory	below a threshold, on `free`	critical below 32 MiB	no

Limits

On IOS-XE, the Processor pool is that of the IOS process only; the memory of the Linux underneath is not in these MIBs.
The name of a pool carries no part: on a stack, the second Processor pool reads Processor # and its index. Which index stands for which member is not verified here without a device.