ASR9001 IOS-XR: show memory vs. SNMP processor memory query

Frank-M · ‎02-13-2019

I have a few ASR-9001-RPs, IOS-XR (6.2.3) with 8GB of memory installed.
"Show mem" looks good - at about 50%

#show memory summary 
Wed Feb 13 06:50:11.483 EST
Physical Memory: 8192M total (4628M available)
 Application Memory : 7994M (4628M available)
 Image: 69M (bootram: 69M)
 Reserved: 128M, IOMem: 0, flashfsys: 0
 Total shared window: 177M

Our monitoring system (Solarwind's N-Able) monitors these routers with the ciscoMemoryPoolUsed/Free OIDs and that results in these values, showing a utilization of >85% (commas inserted to make numbers readable)

snmpget <options> <ip> .1.3.6.1.4.1.9.9.48.1.1.1.2.1
iso.3.6.1.4.1.9.9.48.1.1.1.2.1 = STRING: "processor"
snmpget <options> <ip> .1.3.6.1.4.1.9.9.48.1.1.1.5.1
iso.3.6.1.4.1.9.9.48.1.1.1.5.1 = Gauge32: 3,527,686,248
snmpget <options> <ip> .1.3.6.1.4.1.9.9.48.1.1.1.6.1
iso.3.6.1.4.1.9.9.48.1.1.1.6.1 = Gauge32: 559,738,880

Am I monitoring the wrong OID? Does that OID mean something else than the "show mem" output? Is there a CLI command that would show the same values as the SNMP-OID query?

I'm obviously missing something here, can someone shed light?

Thanks,

Frank

i.voevodin · ‎08-23-2023

It's look like root cause of issue it is that counter is Gauge32

"This means that it can represent a non-negative integer that can increase or decrease, but it cannot exceed a maximum value. This value cannot be greater than 2³²-1 (4294967295 decimal), and the minimum value cannot be smaller than 0 (RFC2578). Therefore, this represent a problem when the memory usage exceed 4GB."

SolarWind explain that problem here: https://thwack.solarwinds.com/product-forums/network-performance-monitor-npm/f/forum/42620/memory-and-cpu-utilization-per-board-cisco-asr9000-ios-xr