Following is how we can retrieve and interpret sensor (power, voltage, current) of a slot/port via SNMP
For example this is the CLI output from 6500 and we want to monitor tx/rx power for Te2/4
#sh interface transceiver detail
Optical High Alarm High Warn Low Warn Low Alarm
Transmit Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
---------- ----------------- ---------- --------- --------- ---------
Te2/1 N/A 4.4 0.4 -8.2 -12.2
Te2/2 -2.5 2.9 -1.0 -7.3 -11.3
Te2/3 N/A 4.4 0.4 -8.2 -12.2
Te2/4 -1.9 4.4 0.4 -8.2 -12.2
Te2/5 -2.5 4.4 0.4 -8.2 -12.2
Te2/6 -2.9 2.9 -1.0 -7.3 -11.3
Te2/7 -2.6 2.9 -1.0 -7.3 -11.3
Optical High Alarm High Warn Low Warn Low Alarm
Receive Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
---------- ----------------- ---------- --------- --------- ---------
Te2/1 N/A 4.4 0.4 -14.4 -18.4
Te2/2 -2.5 2.9 -1.0 -9.9 -13.9
Te2/3 N/A 4.4 0.4 -14.4 -18.4
Te2/4 -8.5 4.4 0.4 -14.4 -18.4
Te2/5 -8.0 4.4 0.4 -14.4 -18.4
Te2/6 -3.4 2.9 -1.0 -9.9 -13.9
Te2/7 -3.0 2.9 -1.0 -9.9 -13.9
Step 1: We need to poll 1.3.6.1.2.1.47.1.1.1.1.2 (entPhysicalDescr) which is part of ENTITY-MIB. This will provide us index and descriptoin of particular sensor which we want to monitor.
Partial output of snmpwalk of 1.3.6.1.2.1.47.1.1.1.1.2 shown below:
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2022 = STRING: "TenGigabitEthernet2/1 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2023 = STRING: "TenGigabitEthernet2/1 Receive Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2035 = STRING: "TenGigabitEthernet2/2 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2036 = STRING: "TenGigabitEthernet2/2 Receive Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2061 = STRING: "TenGigabitEthernet2/4 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2062 = STRING: "TenGigabitEthernet2/4 Receive Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2074 = STRING: "TenGigabitEthernet2/5 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2075 = STRING: "TenGigabitEthernet2/5 Receive Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2087 = STRING: "TenGigabitEthernet2/6 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2088 = STRING: "TenGigabitEthernet2/6 Receive Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2100 = STRING: "TenGigabitEthernet2/7 Transmit Power Sensor"
SNMPv2-SMI::mib-2.47.1.1.1.1.2.2101 = STRING: "TenGigabitEthernet2/7 Receive Power Sensor"
Red highlighted values are indexes of sensors we are interested in.
STEP 2: SNMPWALK of 1.3.6.1.4.1.9.9.91.1.1.1.1.4 (entSensorValue) which is part of CISCO-ENTITY-SENSOR-MIB
Partial output of snmpwalk of 1.3.6.1.4.1.9.9.91.1.1.1.1.4 shown below:
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2022 = INTEGER: 0
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2023 = INTEGER: 0
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2035 = INTEGER: -25
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2036 = INTEGER: -25
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2061 = INTEGER: -19
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2062 = INTEGER: -85
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2074 = INTEGER: -25
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2075 = INTEGER: -80
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2087 = INTEGER: -29
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2088 = INTEGER: -34
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2100 = INTEGER: -26
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2101 = INTEGER: -30
STEP 3: Interpret values
For interpreting values we need to poll below: entSensorType , entSensorScale and entSensorPrecision. Description of these objects given below:
.1.3.6.1.4.1.9.9.91.1.1.1.1.1
entSensorType OBJECT-TYPE
-- FROM CISCO-ENTITY-SENSOR-MIB
-- TEXTUAL CONVENTION SensorDataType
SYNTAX Integer { other(1), unknown(2), voltsAC(3), voltsDC(4), amperes(5), watts(6), hertz(7), celsius(8), percentRH(9), rpm(10), cmm(11), truthvalue(12), specialEnum(13), dBm(14) }
MAX-ACCESS read-only
STATUS Current
DESCRIPTION "This variable indicates the type of data
reported by the entSensorValue.
.1.3.6.1.4.1.9.9.91.1.1.1.1.2
entSensorScale OBJECT-TYPE
-- FROM CISCO-ENTITY-SENSOR-MIB
-- TEXTUAL CONVENTION SensorDataScale
SYNTAX Integer { yocto(1), zepto(2), atto(3), femto(4), pico(5), nano(6), micro(7), milli(8), units(9), kilo(10), mega(11), giga(12), tera(13), exa(14), peta(15), zetta(16), yotta(17) }
MAX-ACCESS read-only
STATUS Current
DESCRIPTION "This variable indicates the exponent to apply
to sensor values reported by entSensorValue.
This variable is set by the agent at start-up
and the value does not change during operation."
1.3.6.1.4.1.9.9.91.1.1.1.1.3
entSensorPrecision OBJECT-TYPE
-- FROM CISCO-ENTITY-SENSOR-MIB
-- TEXTUAL CONVENTION SensorPrecision
SYNTAX Integer (-8..9)
MAX-ACCESS read-only
STATUS Current
DESCRIPTION "This variable indicates the number of decimal
places of precision in fixed-point
sensor values reported by entSensorValue.
This variable is set to 0 when entSensorType
is not a fixed-point type: voltsAC(1), voltsDC(2),
amperes(3), watts(4), hertz(5), celsius(6), or cmm(9).
This variable is set by the agent at start-up
and the value does not change during operation."
Now for example we have to interpret values for transmit and receive power of TE2/4. So
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.1.2061 = INTEGER: 14 -----> means dBm
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.2.2061 = INTEGER: 9 -----> means units
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.3.2061 = INTEGER: 1 -----> number of decimal place is one
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2061 = INTEGER: -19 -----> after placing decimal after one integer value is -1.9 dBm which is actual value
Note:
On nexus entityPhysicalIndex are not supported for slot/port which are required to make correlation between interface and entitySensorValue.
Enhancement request (CSCty93934) for nexus 7k and (CSCui73423) for nexus 5k is opened.
