Solved: Read SNMP "entSensorThresholds" for SFP Transceiver on IOS XE

distahl · ‎07-23-2021

Hi,

I'm trying to use the entSensorThresholds OID to collect the thresholds for optical SFP Modules, but having issues when IOS XE is installed. On old devices with IOS everything is working.

Examples:

WS-C3750X-12S-E / IOS 15.2(4)E10 / Gi1/0/1 -> GLC-SX-MMD

Switch# sh inventory
[...]
NAME: "1", DESCR: "WS-C3750X-12S"
PID: WS-C3750X-12S-E   , VID: V04  , SN: ***
[...]
NAME: "GigabitEthernet1/0/1", DESCR: "1000BaseSX SFP"
PID: GLC-SX-MMD          , VID: V01  , SN: ***
[...]

# find interface (entPhysicalDescr)
snmpwalk [...] 1.3.6.1.2.1.47.1.1.1.1.2 | grep 'GigabitEthernet1/0/1 .*Power Sensor'
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1044 = STRING: "GigabitEthernet1/0/1 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1045 = STRING: "GigabitEthernet1/0/1 Receive Power Sensor"

# get current value (entSensorValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.1.1.1.4 | egrep '\.1044|\.1055'
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1044 = INTEGER: -51
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1055 = INTEGER: 72

# get threshold values (entSensorThresholdValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.2.1.1.4 | egrep '\.1044|\.1055'
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1044.1 = INTEGER: 0
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1044.2 = INTEGER: -30
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1044.3 = INTEGER: -95
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1044.4 = INTEGER: -135
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1055.1 = INTEGER: 150
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1055.2 = INTEGER: 120
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1055.3 = INTEGER: 20
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1055.4 = INTEGER: 10

WS-C3850-12S-E / IOS XE 16.12.4 / Gi1/0/1 -> GLC-SX-MMD

Switch# sh inventory
[...]
NAME: "Switch 1", DESCR: "WS-C3850-12S-E"
PID: WS-C3850-12S-E    , VID: V02  , SN: ***
[...]
NAME: "Gi1/0/1", DESCR: "1000BaseSX SFP"
PID: GLC-SX-MMD          , VID: V03  , SN: *** 
[...]

# find interface (entPhysicalDescr)
snmpwalk [...] 1.3.6.1.2.1.47.1.1.1.1.2 | grep 'GigabitEthernet1/0/1 .*Power Sensor'
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1078 = STRING: "GigabitEthernet1/0/1 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1079 = STRING: "GigabitEthernet1/0/1 Receive Power Sensor"

# get current value (entSensorValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.1.1.1.4 | egrep '\.1078|\.1079'
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1078 = INTEGER: -60
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1079 = INTEGER: -52

# get threshold values (entSensorThresholdValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.2.1.1.4 | egrep '\.1078|\.1079'
  ### noting ###
  
# as another proove, get threshold value for specific index (entSensorThresholdValue.1078)
snmpget -f [...] 1.3.6.1.4.1.9.9.91.1.2.1.1.4.1078
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1078 = No Such Instance currently exists at this OID

C9300-24S / IOS XE 17.3.3 / Gi1/0/1 -> GLC-SX-MMD

Switch# sh inventory
[...]
NAME: "Switch 1", DESCR: "C9300-24S"
PID: C9300-24S         , VID: V01  , SN: ***
[...]
NAME: "Gi1/0/1", DESCR: "1000BaseSX SFP"
PID: GLC-SX-MMD          , VID: V01  , SN: ***
[...]

# find interface (entPhysicalDescr)
snmpwalk [...] 1.3.6.1.2.1.47.1.1.1.1.2 | grep 'GigabitEthernet1/0/1 .*Power Sensor'
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1090 = STRING: "GigabitEthernet1/0/1 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.1091 = STRING: "GigabitEthernet1/0/1 Receive Power Sensor"

# get current value (entSensorValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.1.1.1.4 | egrep '\.1090|\.1091'
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1090 = INTEGER: -50
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1091 = INTEGER: -264

# get threshold values (entSensorThresholdValue)
snmpwalk [...] 1.3.6.1.4.1.9.9.91.1.2.1.1.4 | egrep '\.1090|\.1091'
  ### noting ###
  
# as another proove, get threshold value for specific index (entSensorThresholdValue.1090)
snmpget -f [...] 1.3.6.1.4.1.9.9.91.1.2.1.1.4.1090
SNMPv2-SMI::enterprises.9.9.91.1.2.1.1.4.1090 = No Such Instance currently exists at this OID

So as you can see, the first example, with IOS, is working for entSensorThresholds. But the other two examples aren't working. You can still obtain the current value, but not the thresholds.

Am I doing somthing wrong? Have I missed something? Or is this a bug?

Thnak you.

distahl · ‎07-26-2021

I've opened a TAC case and got following answer.

I did some research and it's confirmed that detailed SFP information given by entSensorThresholdTable is not supported on C3850 and C9300 IOS XE releases so far.

Also, there's an enhancement request opened for it, so the support for this can be included in future release.
You can subscribe to it by clicking in the "Notifications" button, this way you will be receiving periodically updates about the status.
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn58055

View solution in original post

distahl · ‎07-26-2021

I've opened a TAC case and got following answer.

I did some research and it's confirmed that detailed SFP information given by entSensorThresholdTable is not supported on C3850 and C9300 IOS XE releases so far.

Also, there's an enhancement request opened for it, so the support for this can be included in future release.
You can subscribe to it by clicking in the "Notifications" button, this way you will be receiving periodically updates about the status.
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn58055