This article explains the temperature mismatch behavior exhibited by MX2k devices (MX2008, MX2010, MX2020) and also provides the steps to resolve it.
The chassis FPC temperature increases up to 20 degrees Celsius after upgrading Junos version to 17.2.
Check the hardware inventory for FPC type:
user@R1> show chassis hardware
Hardware inventory:
Item Version Part number Serial number Description
Chassis <masked> MX2020
<snip>
FPC 2 REV 26 750-063414 <masked> MPC9E 3D
<snip>
Before Upgrade:
user@host> show chassis fpc 2
Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%)
Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer
2 Online 39 19 0 17 16 11 3136 16 22
user@host> show chassis fpc 2 detail
Slot 2 information:
State Online
Temperature 39 <-- Matches the temperature displayed in show chassis fpc 1
Total CPU DRAM 3136 MB
Total XR2 1028 MB
Total DDR DRAM 24576 MB
<snip>
user@host> show chassis environment fpc 2 | match temp
Temperature Intake 39 degrees C / 86 degrees F
Temperature Exhaust A 53 degrees C / 127 degrees F
Temperature Exhaust B 44 degrees C / 111 degrees F
SNMP Poller output:
user@R1> show snmp mib walk jnxOperatingTemp |match .7.
jnxOperatingTemp.7.1.0.0 = 34
jnxOperatingTemp.7.3.0.0 = 39 <-- This is the Intake Temperature of FPC2 displayed here
jnxOperatingTemp.15.7.0.0 = 41
jnxOperatingTemp.22.7.0.0 = 32
jnxOperatingTemp.22.7.1.0 = 32
jnxOperatingTemp.22.7.2.0 = 32
jnxOperatingTemp.22.17.0.0 = 31
jnxOperatingTemp.22.17.1.0 = 31
jnxOperatingTemp.22.17.2.0 = 31
After Upgrade:
user@host> show chassis fpc 2
Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%)
Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer
2 Online 53 19 0 17 16 11 3136 16 22
user@host> show chassis fpc 2 detail
Slot 2 information:
State Online
Temperature 30 <-- Does not match the temperature displayed in show chassis fpc 1
Total CPU DRAM 3136 MB
Total XR2 1028 MB
Total DDR DRAM 24576 MB
<snip>
user@host> show chassis environment fpc 2 | match temp
Temperature Intake 30 degrees C / 86 degrees F
Temperature Exhaust A 53 degrees C / 127 degrees F
Temperature Exhaust B 44 degrees C / 111 degrees F
Temperature EA0 TSen 53 degrees C / 127 degrees F
Temperature EA0 Chip 47 degrees C / 116 degrees F
Temperature EA0_XR0 TSen 53 degrees C / 127 degrees F
Temperature EA0_XR0 Chip 55 degrees C / 131 degrees F
Temperature EA0_XR1 TSen 53 degrees C / 127 degrees F
Temperature EA0_XR1 Chip 59 degrees C / 138 degrees F
This is seen because show chassis FPC is displaying the Exhaust temperature for FPC and show chassis FPC detail displays the Intake temperature. For detailed temperature values, one can refer show chassis environment output.
Also, from the SNMP output, one can verify that the operating temperature for FPC 2 matches the exhaust temperature unlike as seen on the previous version before the upgrade (where the intake temperature is matched)
SNMP Poller output:
user@R1> show snmp mib walk jnxOperatingTemp |match .7.
jnxOperatingTemp.7.1.0.0 = 34
jnxOperatingTemp.7.3.0.0 = 53 <-- This is the Exhaust Temperature of FPC2 displayed here
jnxOperatingTemp.15.7.0.0 = 41
jnxOperatingTemp.22.7.0.0 = 32
jnxOperatingTemp.22.7.1.0 = 32
jnxOperatingTemp.22.7.2.0 = 32
jnxOperatingTemp.22.17.0.0 = 31
jnxOperatingTemp.22.17.1.0 = 31
jnxOperatingTemp.22.17.2.0 = 31
This is the reason the difference in temperature is seen since the OIDs match different temperature values before and after the upgrade.
- junos:17.3R3-S2
- junos:17.4R2-S2
- junos:17.4R3
- junos:18.1R1
- junos:18.1R2
- junos:18.2X75-D5