Removing an MCS

To remove an MCS, follow this procedure (see Figure 81):

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. Make sure the router is attached to a proper earth ground. For more information about ESD, see Preventing Electrostatic Discharge Damage.
3. 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 the Rear Component Cover.
4. 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.
   • 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
     ...
     
      

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

   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.

   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.

6. On the console or other management device connected to the Routing Engine that is paired with the CB 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 Protocols, Class of Service, and System Basics Command Reference.

7. Push the end of each extractor clip (located at each end of the MCS) outward.
8. Grasp the extractor clips and slide the MCS about halfway out of the chassis.
9. Place one hand under the MCS to support it, slide it completely out of the chassis, and place it on the antistatic mat or in the electrostatic bag.