Troubleshoot the EX5200 Switch

Problem

Cause

Temperature sensors in the chassis monitor the temperature of the chassis. The switch triggers an alarm if a fan fails or if the temperature of the chassis exceeds permissible levels for some other reason.

Solution

When the switch triggers a temperature alarm such as the FPC 0 PFE Die Sensor Temp Too Hot alarm, use the show chassis environment and the show chassis temperature-thresholds commands to identify the condition that triggered the alarm.

CAUTION:

To prevent the switch from overheating, operate it in an area with an ambient temperature within the recommended range. To prevent airflow restriction, allow at least 6 inches (15.2 cm) of clearance around the ventilation openings.

1. Connect to the switch by using Telnet, and issue the show chassis environment command. This command displays environmental information about the switch chassis, including the temperature. The command also displays information about the fans, power supplies, and Routing Engines. Following is a sample show chassis environment output.

   Table 1 lists the output fields for the show chassis environment command. The table lists output fields in the approximate order in which they appear.

   Table 1: show chassis environment Output Fields

   Field Name	Field Description
   Class	Information about the category or class of chassis component: Temp: Temperature of air flowing through the chassis in degrees Celsius (°C) and degrees Fahrenheit (°F) Fans: Information about the status of fans and blowers
   Item	Information about the chassis components: Flexible PIC Concentrators (FPCs)—that is, the line cards Control Boards (CBs) Routing Engines Power entry modules (PEMs)—that is, the power supplies
   Status	Status of the specified chassis component. For example, if Class is Fans, the fan status can be: OK: The fans are operational. Testing: The fans are being tested during initial power-on. Failed: The fans have failed or the fans are not spinning. Absent: The fan tray is not installed.
   Measurement	Depends on the Class. For example, if Class is Temp, indicates the temperature in degrees Celsius (°C) and degrees Fahrenheit (°F). If the Class is Fans, indicates actual fan RPM.

2. Issue the command show chassis temperature-thresholds . This command displays the chassis temperature threshold settings. The following is a sample output.

   The following table lists the output fields for the show chassis temperature-thresholds command. The table lists output fields in the approximate order in which they appear.

   Table 2: show chassis temperature-thresholds Output Fields

   Field Name	Field Description
   Item	Chassis component. You can configure the threshold information for components such as the chassis, the Routing Engines, and FPC for each slot in each FRU to display in the output. By default, information is displayed only for the chassis and the Routing Engines.
   Fan speed	Temperature thresholds, in degrees Celsius, for the fans to operate at normal and at high speed. Normal—The temperature threshold at which the fans operate at normal speed and when all the fans are present and functioning normally. High—The temperature threshold at which the fans operate at high speed or when a fan has failed or is missing. Note: An alarm is triggered when the temperature exceeds the threshold settings for a yellow, amber, or red alarm.
   Yellow or amber alarm	Temperature threshold, in degrees Celsius, that triggers a yellow or amber alarm. Normal—The temperature threshold that must be exceeded on the device to trigger a yellow or amber alarm when the fans are running at full speed. Bad fan—The temperature threshold that must be exceeded on the device to trigger a yellow or amber alarm when one or more fans have failed or are missing.
   Red alarm	Temperature threshold, in degrees Celsius, that triggers a red alarm. Normal—The temperature threshold that must be exceeded on the device to trigger a red alarm when the fans are running at full speed. Bad fan—The temperature threshold that must be exceeded on the device to trigger a red alarm when one or more fans have failed or are missing.
   Fire shutdown	Temperature threshold, in degrees Celsius, at which the switch shuts down in case of fire. Note: In the case of an Extension Module facing this temperature, this Extension Module wil become offline.

When a temperature alarm is triggered, you can identify the condition that triggered it by running the show chassis environment command to display the chassis temperature values for each component and comparing those with the temperature threshold values. You can display the temperature threshold values by running the show chassis temperature-thresholds command.

For example, when you check the reading of PHY Temperature Sensor 1:

• If the temperature of PHY Temperature Sensor 1 is between 96° C and 111° C, the output indicates that the fans are operating at a normal speed (no alarm is triggered).

• If the temperature of PHY Temperature Sensor 1 exceeds 112° C, a yellow alarm is triggered to indicate that one or more fans have failed.

• If the temperature of PHY Temperature Sensor 1 exceeds 113° C, a red alarm is triggered to indicate that one or more fans have failed.

• If the temperature of PHY Temperature Sensor 1 exceeds 114° C, the condition indicates fire shutdown and the switch is powered off.

Table 3 lists the possible causes for the switch to generate a temperature alarm. It also lists the respective remedies.

Table 3: Causes and Remedies for Temperature Alarms

Cause	Remedy
Ambient temperature is above threshold temperature.	Ensure that the ambient temperature is within the threshold temperature limit. See Environmental Specifications.
Fan module or fan tray has failed.	Perform the following steps: Check the fan. Replace the faulty fan module or fan tray. If the above two checks show no problems, open a support case using the Case Manager link at https://www.juniper.net/support/ or call 1-888-314-5822 (toll-free within the United States and Canada) or 1-408-745-9500 (from outside the United States).
Restricted airflow through the switch due to insufficient clearance around the installed switch.	Ensure that there is sufficient clearance around the installed switch.