Removing a Routing Engine

To remove a Routing Engine, follow this procedure (see Figure 78):

1. Place an electrostatic bag or antistatic mat on a flat, stable surface.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and connect the strap to one of the ESD points on the chassis. Verify that the router is attached to a proper earth ground. For more information about ESD, see Preventing Electrostatic Discharge Damage.
3. If two Routing Engines are installed, use one of the following two methods to determine which is functioning as master:
   • Note which of the blue Routing Engine MASTER LEDs is lit on the Routing Engine panel or craft interface.
   • Issue the following CLI command. The master Routing Engine is designated Master in the Current state field:
     user@host> show chassis routing-engine

         Routing Engine status:      Slot 0:     Current state                 Master ...  

4. If the Routing Engine you are removing is the master and a second Routing Engine is installed, issue the following CLI command to switch mastership to the standby Routing Engine:
   user@host> request chassis routing-engine master switch

   The backup Routing Engine immediately assumes Routing Engine functions. If graceful switchover and nonstop routing are configured, packet forwarding and routing are continued without interruption. If the Routing Engines are configured for graceful switchover , but nonstop routing is not configured, there is no interruption to packet forwarding, but routing is interrupted momentarily. If neither graceful switchover nor nonstop routing is configured, packet forwarding halts while the backup 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 and nonstop routing, see the section about Routing Engine redundancy in the JUNOS System Basics Configuration Guide.

   We recommend you run JUNOS Release 7.0 or later on the M20 router to support graceful switchover.

   Note: Router performance might change if the backup 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.

5. On the console or other management device connected to the Routing Engine you are removing, enter CLI operational mode and issue the following command. The command shuts down the Routing Engine cleanly, so its state information is preserved:
   user@host> request system halt

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

   For more information about the command, see the JUNOS System Basics and Services Command Reference.

6. Using your thumbs, push and hold the red tab on each extractor clip toward the outer edge of the unit. Push the ends of the extractor clips outward to unseat the Routing Engine from the chassis.
7. Grasp the extractor clips and slide the unit about halfway out of the chassis.

   Caution: Slide the Routing Engine straight out of the chassis. Damage can result if the Routing Engine 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.

Figure 78: Removing a Routing Engine