Replacing the T320 Host Subsystem Components
To replace a host subsystem, perform the following
procedures:
Taking the T320 Host Subsystem Offline
The host subsystem is taken offline and brought online as a
unit. Before you replace a control board or Routing Engine, you must
take the host subsystem offline.
Normally, if two host subsystems are installed in the 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.
Table 1: Effect
of Taking the T320 Host Subsystem Offline
Type of Host Subsystem | Effect of taking the Host Subsystem Offline |
|---|
Nonredundant host subsystem | The router shuts down. |
Backup host subsystem | The functioning of the router is not interrupted. The
backup host subsystem is hot-removable and hot-insertable. |
Master host subsystem | The backup host subsystem becomes the master. The backup
Routing Engine assumes Routing Engine functions. The master host subsystem
is hot-pluggable. Removal or failure of the master Routing Engine
affects forwarding and routing based on the high availability configuration: - Dual Routing Engines without any high availability features
enabled—Traffic is interrupted while the Packet Forwarding Engine
is reinitialized. All kernel and forwarding processes are restarted.
When the switchover to the new master Routing Engine is complete,
routing convergence takes place and traffic is resumed.
- Graceful Routing Engine switchover (GRES) is enabled—Graceful
Routing Engine switchover preserves interface and kernel information.
Traffic is not interrupted. However, graceful Routing Engine switchover
does not preserve the control plane. Neighboring routers detect that
the router has restarted and react to the event in a manner prescribed
by individual routing protocol specifications. To preserve routing
without interruption during a switchover, graceful Routing Engine
switchover must be combined with nonstop active routing.
- Nonstop active routing is enabled (graceful Routing Engine
switchover must be configured for nonstop active routing to be enabled)—Nonstop
active routing supports Routing Engine switchover without alerting
peer nodes that a change has occurred. Nonstop active routing uses
the same infrastructure as graceful Routing Engine switchover to preserve
interface and kernel information. However, nonstop active routing
also preserves routing information and protocol sessions by running
the routing protocol process (rpd) on both Routing Engines. In addition,
nonstop active routing preserves TCP connections maintained in the
kernel.
- Graceful restart is configured—Graceful restart
provides extensions to routing protocols so that neighboring helper
routers restore routing information to a restarting router. These
extensions signal neighboring routers about the graceful restart and
prevent the neighbors from reacting to the router restart and from
propagating the change in state to the network during the graceful
restart period. Neighbors provide the routing information that enables
the restarting router to stop and restart routing protocols without
causing network reconvergence. Neighbors are required to support
graceful restart. The routing protocol process (rpd) restarts. A graceful
restart interval is required. For certain protocols, a significant
change in the network can cause graceful restart to stop.
|
 | 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:
The first supported release for graceful Routing Engine
switchover and nonstop active routing on the T320 router is Junos
OS Release 7.0 and Junos OS Release 8.4, respectively. Graceful restart
software requirements are dependent on the routing protocols configured
on the router. For the minimum software requirements for graceful
restart, see the Junos OS High Availability Configuration Guide . |
To take a host subsystem offline:
- 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
...
- 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
- To halt the Routing Engine:
user@host> request system halt
The command shuts down the Routing Engine cleanly,
so its state information is preserved. For more information about
the command, see the Junos OS System Basics and Services Command Reference
.
 | Note:
The SIBs might continue forwarding traffic for approximately
five minutes after the request system halt command has been
issued. |
- On the console or other management device connected to
the other Routing Engine, enter CLI operational mode and issue the
following command.
user@host> request chassis cb offline slot n
n is 0 or 1 for the slot number of the
host subsystem being taken offline.
- Verify that the control board is offline:
user@host> show chassis environment cb
Replacing a T320 Standard Control Board or T-CB
The router can have up to
two control boards. 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 standard control board or T-CB, perform the following
procedures:
- Removing a T320 Standard Control Board or T-CB
- Installing a T320 Standard Control Board or T-CB
Removing a T320 Standard Control Board or T-CB
 | Caution:
Before you replace a control board, 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 T320 Host Subsystem Offline. |
 | Caution:
If the control board 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 T320 Host Subsystem Offline. |
To remove a standard control board or T-CB (see Figure 1):
- Take the host subsystem offline. See Taking the T320 Host Subsystem Offline.
- 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. .
- Loosen the captive screws (using a Phillips (+) screwdriver,
number 2) on the ejector handles on both sides of the control
board faceplate.
- Flip the ejector handles outward to unseat the control
board.
- Grasp the ejector handles and slide the control board
about halfway out of the chassis.
- Place one hand underneath the control board to support
it and slide it completely out of the chassis.
- Place the control board on the antistatic mat.
- If you are not replacing the control board now, install
a blank panel over the empty slot.
Figure 1: Removing a T320 Standard
Control Board
Installing a T320 Standard Control Board or T-CB
To install a standard control board or T-CB (see Figure 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.
- Carefully align the sides of the control board with the
guides inside the chassis.
- Slide the control board into the chassis, carefully ensuring
that it is correctly aligned.
- Grasp both ejector handles, and press them inward to seat
the control board.
- Tighten the captive screws on the ejector handles, using
a Phillips (+) screwdriver, number 2.
 | Note:
If power is applied to the Routing Engine and its corresponding
control board is functioning normally, the control board comes online
automatically. |
Verify that the control board is functioning normally,
- Check the LEDs on the control board faceplate. The green OK LED should light steadily a few minutes after the control
board is installed. If the FAIL LED is lit steadily, remove
and install the control board again.
If the FAIL LED still lights steadily, the control board
is not functioning properly. Contact your customer support representative.
- Use the CLI command show chassis environment cb to check the status of the control board,
Figure 2: Installing a Standard Control
Board
Replacing a T320 PC Card
- Removing a T320 PC Card
- Installing a T320 PC Card
Removing a T320 PC Card
The PC card is inserted into the slot labeled PC CARD on the RE-600 or RE-1600. To remove the PC card (see Figure 3):
- 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 Routing Engine cover by loosening the captive
screws on the corners of its faceplate.
- 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. |
- The PC card pops partially out of the slot. Grasp the
card and pull it completely out of the slot.
- Place the PC card on the antistatic mat.
- 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.
Figure 3: Removing a PC Card
Installing a T320 PC Card
To install a PC card (see Figure 4):
- Attach an electrostatic discharge (ESD) grounding strap
to your bare wrist, and connect the strap to one of the ESD points
on the chassis.
- If the Routing Engine cover is in place, remove the cover
by loosening the captive screws on the corners of its faceplate.
- 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 RE-1600 has two PC Card slots. In this case, use either
slot. Do not install more than one PC card in the Routing Engine. |
- Press the card firmly all the way into the slot.
- Reinstall the Routing Engine cover and tighten the screws
on the corners of the cover to secure it to the chassis.
Figure 4: Installing a PC Card
Replacing a DIMM Module in T320 Routing Engines
- Removing a T320 DIMM Module
- Installing a T320 DIMM Module
Removing a T320 DIMM Module
The DIMM modules are located on the top of the Routing Engine.
To remove a DIMM module:
- 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 Routing Engine.
- 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.
- 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.
- Place the DIMM module on the antistatic mat or in the
electrostatic bag.
- Push the plastic ejectors to close the empty DIMM module
slot.
Installing a T320 DIMM Module
To insert a DIMM module into the Routing Engine:
- 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 DIMM module from its electrostatic bag.
- To open the empty DIMM slot, press the plastic ejectors
open.
- Grasp the DIMM module by the edges, being careful not
to touch any electrical components.
- Pressing firmly on both ends, push the module into the
slot until the ejectors return completely to the closed position.
- Install the Routing Engine.
- You can view the SDRAM configuration and verify the DIMM
was installed correctly by issuing the show chassis routing-engine command.
Figure 5: Installing the DIMM Module
Replacing a T320 Routing Engine
To replace a Routing Engine,
perform the following procedures:
- Removing a T320 Routing Engine
- Installing a T320 Routing Engine
Removing a T320 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 1.9 lb (0.9 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. . |
 | 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. |
To remove a Routing Engine (see Figure 7):
- Take the host subsystem offline as described in Taking the T320 Host Subsystem Offline.
- 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.
- If the Routing Engine cover is in place, remove the cover
by loosening the captive screws on the corners of its faceplate (see Figure 6).
- If applicable, loosen the screws on the extractor handles
at either end of the Routing Engine faceplate, using a Phillips screwdriver.
- Press the red tabs on the ejector handles on both sides
of the Routing Engine faceplate.
- Flip the ejector handles outward to unseat the Routing
Engine.
- Grasp the Routing Engine by the ejector handles and slide
it about halfway out of the chassis.
- Place one of your hands underneath the Routing Engine
to support it and slide it completely out of the chassis.
- Place the Routing Engine on the antistatic mat.
- 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 Figure 8).
Figure 6: Removing the T320
Routing Engine Cover
Figure 7: Removing a T320 Routing
Engine
Figure 8: Reinstalling
the T320 Routing Engine Cover
Installing a T320 Routing Engine
To install a Routing Engine (see Figure 9):
- Attach an electrostatic discharge (ESD) grounding strap to your
bare wrist, and connect the strap to one of the ESD points on the
chassis.
- Ensure that the ejector handles are not in the locked position.
If necessary, press the red tabs and flip the ejector handles outward.
- Place one hand underneath the Routing Engine to support it. With
the other hand, grasp one of the ejector handles on the faceplate.
- Carefully align the sides of the Routing Engine
with the guides inside the chassis.
- Slide the Routing Engine into the chassis until
you feel resistance, then press the Routing Engine's faceplate until
it engages the midplane connectors.
- Press both the ejector handles inward to seat the
Routing Engine.
The Routing Engine might require several minutes to boot.
- 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.
- 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 10).
- If the router is powered on and the Routing Engine's corresponding
control board 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. 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 System Basics and Services Command Reference
.
Figure 9: Installing a T320 Routing
Engine
Figure 10: Reinstalling the T320
Routing Engine Cover
Published: 2011-12-19