Related Documentation
- EX Series
- Synchronizing Routing Engines
- M Series
- M40e Field-Replaceable Units (FRUs)
- Tools and Parts Required to Remove Components from an M40e Router
- M40e Routing Engine Description
- Routing Engine Interface Cable and Wire Specifications for the M40e Router
- Synchronizing Routing Engines
- MX Series
- Synchronizing Routing Engines
- T Series
- Synchronizing Routing Engines
Replacing an M40e Routing Engine
The router can have a Routing Engine in each of the slots labeled RE0 and RE1 at the rear of the chassis, as shown in Figure 1. Each Routing Engine weighs approximately 1.5 lb (0.7 kg).
The Routing Engines are hot-pluggable. For a description of the effect of removing a Routing Engine, see M40e Host Module Description.
Figure 1: Rear of M40e Chassis with Component Cover Removed

Removing a Routing Engine from an M40e Router
To remove a Routing Engine from an M40e router:
- Place an electrostatic bag or antistatic mat on a flat, stable surface.
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Remove the rear component cover by loosening the thumbscrew at each corner of the cover and pulling it straight off the chassis. For complete instructions, see Removing Components from the Chassis Before Installing the M40e Router Without a Lift.
- If two host modules are installed, use one of the
following two methods to determine which is functioning as master:
- Note which of the green host module MASTER LEDs is lit on the craft interface.
- The master Routing Engine is designated Master in the Current state field when you issue the command:
user@host> show chassis routing-engine
Routing Engine status: Slot 0: Current state Master ...
- If the component you are removing belongs
to the master host module and a second host module is installed, switch
mastership to the standby host module by issuing the CLI command:
user@host> request chassis routing-engine master switch
For more information about switching host module mastership, see M40e Host Module Description.
- 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
Wait until a message appears on the console confirming that the operating system has halted.
For more information about the command, see the Junos OS System Basics and Services Command Reference.
Note: The SFM might continue forwarding traffic for approximately 5 minutes after the request system halt command has been issued.
- 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.
- 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.
- 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 2: Removing a Routing Engine from an M40e Router

Installing a Routing Engine in an M40e Router
To install a Routing Engine in an M40e router:
- 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 extractor clip at each end of the Routing Engine is flipped toward the outer edge of the unit. If necessary, use your thumbs to push and hold the red tab on each extractor clip toward the outer edge, then push the ends of the extractor clips outward.
- Place one hand under the Routing Engine to support it and grasp one of the extractor clips on the faceplate with the other hand.
- Align the rear of the Routing Engine with the guide
rails inside the chassis and slide it in completely.
Caution: Align the Routing Engine carefully with the guide rails and push it in evenly. Damage can result if the Routing Engine gets lodged in the rails because of uneven movement.
- Press the extractor clip at each end of the Routing Engine inward to seat the unit firmly in the chassis.
- Check the host module LEDs on the craft interface
to verify that the green LED labeled ONLINE is lit for the
host module to which the Routing Engine belongs (M40e Craft Interface Description shows
the LEDs).
You can also verify correct Routing Engine functioning by issuing the show chassis routing-engine command described in Maintaining the M40e Host Module Components.
- Reinstall the rear component cover and tighten
the thumbscrew at each corner to secure it to the chassis. For complete
instructions, see Reinstalling the M40e Components into the Chassis.
Caution: To maintain proper airflow and provide electromagnetic shielding, do not operate the router without the rear component cover in place.
Figure 3: Installing a Routing Engine in an M40e Router

Related Documentation
- EX Series
- Synchronizing Routing Engines
- M Series
- M40e Field-Replaceable Units (FRUs)
- Tools and Parts Required to Remove Components from an M40e Router
- M40e Routing Engine Description
- Routing Engine Interface Cable and Wire Specifications for the M40e Router
- Synchronizing Routing Engines
- MX Series
- Synchronizing Routing Engines
- T Series
- Synchronizing Routing Engines