• Supported Platforms
• T640 Routers

• Related Topics
• T640 Preventing Electrostatic Discharge Damage
• T640 Host Subsystem Description
• Taking the T640 Host Subsystem Offline
• Maintaining the T640 Host Subsystem
• T640 Routing Engine Functions
• T640 Routing Engine Interface Cable and Wire Specifications

Replacing the T640 Host Subsystem Components

To replace a routing engine or control board:

1. Taking the T640 Host Subsystem Offline
2. Replacing a T640 T-CB
3. Replacing a T640 PC Card
4. Replacing a DIMM Module in T640 Routing Engines
5. Replacing a T640 Routing Engine

Taking the T640 Host Subsystem Offline

The host subsystem is taken offline and brought online as a unit. Before you replace a T-CB or Routing Engine, you must take the host subsystem offline.

Normally, if two host subsystems are installed in the T640 router, RE0 functions as the master and RE1 functions as the backup. You can remove the backup host subsystem (or either of its components) without interrupting the functioning of the router. If you take the master host subsystem offline, the backup host subsystem becomes the master (the router might reboot, depending on your configuration). If the router has only one host subsystem, taking the host subsystem offline causes the router to shut down.

Table 1 explains the effect of taking the host subsystem offline.

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 each Routing Engine.

Note: For information about configuring graceful Routing Engine switchover, graceful restart, and nonstop active routing, see the Junos High Availability Configuration Guide.

Note: The first supported release for graceful Routing Engine switchover and nonstop active routing on the T640 router is Junos OS Release 7.0 and Junos OS Release 8.4, respectively. Graceful restart software requirements depend on the routing protocols configured on the router. For the minimum software requirements for graceful restart, see the Junos High Availability Configuration Guide.

To take a host subsystem offline:

1. Determine whether the host subsystem is functioning as the master or as the backup, using one of the two following methods:
   • Check the Routing Engine LEDs on the craft interface. If the green MASTER LED is lit, the corresponding host subsystem is functioning as the master.
   • 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 
       Election priority         Master (default) 
       Temperature            34 degrees C / 93 degrees F
         DRAM               2048 Mbytes
         CPU utilization: 
         User                  0 percent 
         Background            0 percent 
         Kernel                1 percent 
         Interrupt             0 percent 
         Idle                 99 percent 
         Start time              2002-01-22 05:21:31 UTC
         Uptime                  10 days, 16 hours, 4 minutes, 52 seconds
         Load averages:          1 minute   5 minute  15 minute
                                     0.00       0.00       0.00
     Routing Engine status:
       Slot 1: 
       Current state             Empty
     

2. If the host subsystem is functioning as the master, switch it to backup using the CLI command:
   
   

   user@host> request chassis routing-engine master switch
3. To halt the router:
   
   

   user@host> request system halt

   (If two Routing Engines are installed, also issue the command on the backup Routing Engine.) Wait until a message appears on the console confirming that the operating system has halted.

   The command shuts down the Routing Engine cleanly, so its state information is preserved. For more information about the command, see the Junos System Basics and Services Command Reference.

   Note: The SIBs might continue forwarding traffic for approximately 5minutes after the request system halt command has been issued.

Replacing a T640 T-CB

The router can have up to two T-CBs. They are located in the upper rear of the chassis in the slots marked CB0 and CB1. Each weighs approximately 5 lb (2.3 kg).

To replace a T-CB, perform the following procedures:

• Removing a T640 T-CB
• Installing a T640 T-CB

Removing a T640 T-CB

Caution: Before you replace a T-CB, you must take the host subsystem offline. If there is only one host subsystem, taking the host subsystem offline shuts down the router. See Taking the T640 Host Subsystem Offline.

Caution: If the T-CB to be replaced is associated with the Routing Engine currently functioning as the master Routing Engine, switch it to the backup before removing the T-CB. See Taking the T640 Host Subsystem Offline.

To remove a T-CB (see Figure 1):

1. Take the host subsystem offline. See Taking the T640 Host Subsystem Offline.
2. Place an electrostatic bag or antistatic mat on a flat, stable surface.
3. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis. For more information about ESD, see T640 Preventing Electrostatic Discharge Damage.
4. If the router is connected to a TX matrix platform, disconnect the cable plugged into the port labeled CIP.
5. Loosen the captive screws (using a Phillips (+) screwdriver, number 2) on the ejector handles on both sides of the T-CB faceplate.
6. Flip the ejector handles outward to unseat the T-CB.
7. Grasp the ejector handles, and slide the T-CB about halfway out of the chassis.
8. Place one hand underneath the T-CB to support it, and slide it completely out of the chassis.
9. Place the T-CB on the antistatic mat.
10. If you are not replacing the T-CB now, install a blank panel over the empty slot.

Installing a T640 T-CB

To install a T-CB (see Figure 2):

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
2. Carefully align the sides of the T-CB with the guides inside the chassis.
3. Slide the T-CB into the chassis, carefully ensuring that it is correctly aligned.
4. Grasp both ejector handles, and press them inward to seat the T-CB.
5. Tighten the captive screws on the ejector handles, using a Phillips (+) screwdriver, number 2.
6. If applicable, reconnect the cable previously plugged into the CIP port.
7. If power is applied to the Routing Engine and its corresponding T-CB is functioning normally, the T-CB comes online automatically. To verify that the T-CB is functioning normally, check the LEDs on its faceplate. The green OK LED should light steadily a few minutes after the T-CB is installed. If the FAIL LED is lit steadily, remove and install the T-CB again. If the FAIL LED still lights steadily, the T-CB is not functioning properly. Contact your customer support representative.

   To check the status of the T-CB, use the CLI command:

   
   

   user@host> show chassis environment cb

Replacing a T640 PC Card

A slot labeled PC CARD on the Routing Engine faceplate accepts a Type I PC Card, as defined in the PC Card Standard published by the Personal Computer Memory Card International Association (PCMCIA). The router is shipped with a PC Card that contains Junos OS. The PC Card can be used to copy Junos OS from the PC Card onto the Routing Engine. You can also copy Junos OS from the Routing Engine onto a PC Card, for example, to create a backup copy of upgrade software that you have obtained from Juniper Networks. Instructions for copying software to a PC Card are available at the Juniper Networks Support Web site (http://www.juniper.net/support/). After logging in, navigate to the Customer Support Center, then to the download page for Junos OS.

Note: The software on a PC Card is loaded only onto the Routing Engine into which the PC Card is inserted. It is not automatically copied to the other Routing Engine.

To replace a PC Card, perform the following procedures:

• Removing a T640 PC Card
• Installing a T640 PC Card

Removing a T640 PC Card

The PC Card is located in the slot labeled PC CARD on the Routing Engine. To remove the PC Card (see Figure 3):

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. For more information about ESD, see T640 Preventing Electrostatic Discharge Damage.
3. Remove the Routing Engine cover by loosening the captive screws on the corners of its faceplate.
4. On the Routing Engine faceplate, press the eject button on the right side of the PC Card slot once to release the button. Press again to release the PC Card.

   Note: The Routing Engine in your router might have two PC Card slots. In this case, use either slot. Do not install more than one PC Card in the Routing Engine.

5. The PC Card pops partially out of the slot. Grasp the card and pull it completely out of the slot.
6. Place the PC Card on the antistatic mat.
7. If you are not replacing the PC Card now, reinstall the Routing Engine cover and tighten the screws on the corners of the cover to secure it to the chassis.

Installing a T640 PC Card

To install a PC Card (see Figure 4):

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis. For more information about ESD, see T640 Preventing Electrostatic Discharge Damage.
2. If the Routing Engine cover is in place, remove the cover by loosening the captive screws on the corners of its faceplate.
3. Insert the PC Card into the PC Card slot on the Routing Engine, with the Juniper Networks logo facing downward.

   Caution: Be sure to insert the PC Card with the label facing downward. Inserting the PC Card incorrectly might damage the Routing Engine.

   Note: The Routing Engine in your router might have two PC Card slots. In this case, use either slot. Do not install more than one PC Card in the Routing Engine.

4. Press the card firmly all the way into the slot.
5. Reinstall the Routing Engine cover and tighten the screws on the corners of the cover to secure it to the chassis.

Replacing a DIMM Module in T640 Routing Engines

1. Removing a T640 DIMM Module
2. Installing a T640 DIMM Module

Removing a T640 DIMM Module

The DIMM modules are located on the top of the Routing Engine. To remove a DIMM module:

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.
3. Remove the Routing Engine.
4. Depending on which Routing Engine you are using, there are two different procedures for ejecting the DIMMs:
   • For Routing Engines with an ejector on one side of the DIMM, press the plastic ejector of the DIMM module. The edge of the module raises upward.
   • For Routing Engines with ejectors on each side of the DIMM, press the plastic ejectors on both sides of the DIMM module.
5. Grasp the DIMM module, being careful not to touch any electrical components on the module, and firmly pull it out of the slot on the Routing Engine.
6. Place the DIMM module on the antistatic mat or in the electrostatic bag.
7. Push the plastic ejectors to close the empty DIMM module slot.

Installing a T640 DIMM Module

To insert a DIMM module into the Routing Engine:

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
2. Remove the DIMM module from its electrostatic bag.
3. To open the empty DIMM slot, press the plastic ejectors open.
4. Grasp the DIMM module by the edges, being careful not to touch any electrical components.
5. Pressing firmly on both ends, push the module into the slot until the ejectors return completely to the closed position.
6. Install the Routing Engine.
7. You can view the the SDRAM configuration and verify the DIMM was installed correctly by issuing the show chassis routing-engine command.

Replacing a T640 Routing Engine

To replace a Routing Engine, perform the following procedures:

• Removing a T640 Routing Engine
• Installing a T640 Routing Engine

Removing a T640 Routing Engine

The router can have one or two Routing Engines. They are located in the upper rear of the chassis in the slots marked RE0 and RE1. Each Routing Engine can weigh up to 2.4 lb (1.1 kg).

Caution: Before you replace a Routing Engine, you must take the host subsystem offline. If there is only one host subsystem, taking the host subsystem offline shuts down the router. See Taking the T640 Host Subsystem Offline.

Caution: If the Routing Engine to be replaced is currently functioning as the master Routing engine, switch it to be the backup before removing it. See Taking the T640 Host Subsystem Offline.

To remove a Routing Engine:

1. Take the host subsystem offline as described in Taking the T640 Host Subsystem Offline.
2. Place an electrostatic bag or antistatic mat on a flat, stable surface.
3. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis. For more information about ESD, see T640 Preventing Electrostatic Discharge Damage.
4. Loosen the captive screws on the corners of the Routing Engine cover.
5. Grasp the Routing Engine cover by its edges, and pull it free from the chassis (see Figure 6).
6. If applicable, loosen the screws on the extractor handles at either end of the Routing Engine faceplate, using a Phillips screwdriver.
7. Press the red tabs on the ejector handles on both sides of the Routing Engine faceplate.
8. Flip the ejector handles outward to unseat the Routing Engine.
9. Grasp the Routing Engine by the ejector handles, and slide it about halfway out of the chassis.
10. Place one of your hands underneath the Routing Engine to support it and slide it completely out of the chassis.
11. Place the Routing Engine on the antistatic mat.
12. If you are not replacing the Routing Engine now, reinstall the Routing Engine cover and tighten the screws on the corners of the cover to secure it to the chassis (see Reinstalling the Routing Engine Cover).

Installing a T640 Routing Engine

To install a Routing Engine (see Figure 8):

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis. For more information about ESD, see T640 Preventing Electrostatic Discharge Damage.
2. Ensure that the ejector handles are not in the locked position. If necessary, press the red tabs and flip the ejector handles outward.
3. Place one hand underneath the Routing Engine to support it. With the other hand, grasp one of the ejector handles on the faceplate.
4. Carefully align the sides of the Routing Engine with the guides inside the chassis.
5. Slide the Routing Engine into the chassis until you feel resistance, then press the Routing Engine's faceplate until it engages the midplane connectors.
6. Press both the ejector handles inward to seat the Routing Engine.

   The Routing Engine might require several minutes to boot.

7. If applicable, tighten the screws on the extractor handles, using a Phillips screwdriver. Be sure to tighten the screws enough to seat the Routing Engine properly.
8. Press the Routing Engine cover into place, then tighten the captive screws on the corners of the cover to secure it to the chassis (see Figure 9).
9. If the router is powered on and the Routing Engine's corresponding T-CB is functioning normally, the Routing Engine comes online automatically. To verify that the Routing Engine is installed correctly, check the HOST0 and HOST1 LEDs on the craft interface. If the router is operational and the Routing Engine is functioning properly, the green OK LED lights steadily. If the red FAIL LED lights steadily instead, remove and install the Routing Engine again (see Removing a T640 Routing Engine and Installing a T640 Routing Engine). If the red FAIL LED still lights steadily, the Routing Engine is not functioning properly. Contact your customer support representative.

   To check the status of the Routing Engine, use the CLI command:

   
   

   user@host> show chassis routing-engine

   For more information about using the CLI, see the Junos OS manuals.