Step 1: Remove an HCM

The HCM is hot-pluggable. You can perform a swap test on an HCM to try to pinpoint the problem.

Action

To remove an HCM, follow these steps:

1. Place an electrostatic bag or antistatic mat on a flat, stable surface.
2. If a Routing Engine is installed in the same row as the HCM you are removing, remove the Routing Engine first. If two Routing Engines are installed, use one of the following two methods to determine which HCM is functioning as master:

• Note which of the blue MASTER LEDs is lit on the Routing Engine faceplates.
• Use the following CLI command:

user@host> show chassis environment hcm

        HCM 0 status:

              State                           Online Master

              FPGA Revision                27

        HCM 1 status:

              State                           Online Standby

              FPGA Revision                27

The master HCM is designated Master in the State field.

3. If you are removing the master Routing Engine and a second Routing Engine is installed, issue the following CLI command to switch mastership to the standby host module:

user@host> request chassis routing-engine master switch

        warning: Traffic will be interrupted while the PFE is re-initialized

        Toggle mastership between routing engines ? [yes,no] (no) yes 

        Resolving mastership...

If the Routing Engines are running JUNOS Release 6.0 or later and are configured for graceful switchover, the standby Routing Engine immediately assumes Routing Engine functions and there is no interruption to packet forwarding. Otherwise, packet forwarding halts while the standby Routing Engine becomes the master and the Packet Forwarding Engine components reset and connect to the new master Routing Engine. For information about configuring graceful switchover, see the section about Routing Engine redundancy in the JUNOS System Basics Configuration Guide.

NOTE: Router performance might change if the standby Routing Engine's configuration differs from the former master's configuration. For the most predictable performance, configure the two Routing Engines identically, except for parameters unique to a Routing Engine, such as the hostname defined at the [edit system] hierarchy level and the management interface (fxp0 or equivalent) defined at the [edit interfaces] hierarchy level. To configure Routing Engine-specific parameters and still use the same configuration on both Routing Engines, include the appropriate configuration statements under the re0 and re1 statements at the [edit groups] hierarchy level and use the apply-groups statement. For instructions, see the JUNOS System Basics Configuration Guide.

4. On the console or other management device connected to the Routing Engine, enter CLI operational mode and use the following command to shut down the router software cleanly and preserve Routing Engine state information:

user@host> request system halt

Wait until a message appears on the console confirming that the operating system has halted.

For more information about the command, see the JUNOS Protocols, Class of Service, and System Basics Command Reference.

NOTE: The router might continue forwarding traffic for a few minutes after the request system halt command has been issued.

5. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and connect the strap to one of the ESD points on the chassis.
6. Loosen the thumbscrews located at each end of the Routing Engine faceplate, using a Phillips screwdriver if necessary.
7. Grasp the handle and slide the unit about halfway out of the chassis.
   

   CAUTION: Slide the Routing Engine straight out of the chassis. Damage can result if it gets lodged because of uneven movement.

   
   
8. Place one hand under the Routing Engine to support it, slide it completely out of the chassis, and place it on the antistatic mat or in the electrostatic bag.
9. Grasp the handle of the HCM and slide the unit about halfway out of the chassis.
   

   CAUTION: Slide the HCM straight out of the chassis. Damage can result if it gets lodged because of uneven movement.

   
   
10. Place one hand under the HCM to support it, slide it completely out of the chassis, and place it on the antistatic mat or in the electrostatic bag.