Chapter 19
Monitoring the Cooling System
You monitor and maintain the cooling system to keep an acceptable operating
temperature for the router chassis and its components. (See Table 67.)
Table 67: Checklist for Monitoring the Cooling System
Monitor Cooling System Tasks
Command or Action
Understanding the Cooling System on page 252
M5 and M10 Router Cooling Systems on page 253
M7i Router Cooling System on page 253
M10i Router Cooling System on page 254
M20 Router Cooling System on page 255
M40 Router Cooling System on page 256
M40e and M160 Router Cooling Systems on page 259
M320 Router Cooling System on page 261
T320 Router and T640 Routing Node Cooling Systems on page 263
Checking the Cooling System Status on page 267
show chassis environment
Checking the Cooling System Alarms on page 269
1. Check the Alarm Indicators on the Craft Interface on
page 270
show chassis craft-interface
Check the router craft interface.
2. Display Current Cooling System Alarms on page 270
show chassis alarms
3. Display Cooling System Error Messages in the System Log
File on page 271
show log messages | match fan
Maintaining the Air Filter on page 272
Inspect the air filter. If dirty, clean it; if damaged, replace it.
Verifying a Fan Failure on page 272
Perform a swap test on the fan. If defective, replace it without
powering down the router.
Verifying an Impeller Failure on page 273
Feel the impeller air exhaust. If no airflow, replace without
powering down the router.
Replacing a Cooling System Component on page 273
Follow the procedure in the appropriate router hardware
guide.
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Understanding the Cooling System
Purpose
Inspect the router cooling system to ensure that air is flowing through the router to
cool the components installed in the router chassis. If the router temperature
exceeds the critical level, the router automatically shuts down.
What Is the Cooling
System
The cooling system includes the fans and impellers that provide cooling in the
router chassis to