Routing Engines for the M320 and T320 Routers, T640 and T1600 Routing Node, and TX Matrix Platform

The Routing Engine is an Intel-based Peripheral Component Interconnect (PCI) platform that runs JUNOS software. Software processes that run on the Routing Engine maintain the routing tables, manage the routing protocols used on the routing platform, control the router's interfaces, control some chassis components, and provide the interface for system management and user access to the routing platform.

You can install one or two Routing Engines in the routing platform. The Routing Engines install into the upper rear of the chassis in the slots labeled RE0 and RE1. If two Routing Engines are installed, one functions as the master and the other acts as the backup. If the master Routing Engine fails or is removed and the backup is configured appropriately, the backup takes over as the master.

If the host system is redundant, the backup Routing Engine is hot-removable and hot-insertable, but the master Routing Engine is hot-pluggable. A Routing Engine that is not redundant is hot-pluggable. Each Routing Engine requires a Control Board (CB) or T640-specific Control Board (T-CB) to be installed in the adjacent slot. RE0 installs below CB0, and RE1 installs above CB1. A Routing Engine does not power on if no CB or T-CB is present in the adjacent slot.

Routing Engine Components

Each Routing Engine (shown in Figure 16 and Figure 17) consists of the following components:

• CPU—Runs JUNOS software to maintain the routing platform's routing tables and routing protocols. It has a Pentium-class processor.
• DRAM—Provides storage for the routing and forwarding tables and for other Routing Engine processes.
• Internal flash disk—Provides primary storage for software images, configuration files, and microcode. The drive is a fixed compact flask disk and is inaccessible from outside the routing platform.
• Hard disk—Provides secondary storage for log files, memory dumps, and rebooting the system if the internal flash disk fails.
• PC Card slots—Accept removable PC Cards, which store software images for system upgrades. Supported on RE-1600-2048 only.
• USB port—Provides a removable media interface through which you can install the JUNOS software manually (see Figure 13). JUNOS supports USB version 1.0. Supported on RE-A-2000-4096 only.
• LED—Indicates disk activity for the internal IDE interface. It does not necessarily indicate routing-related activity.
• Interfaces for out-of-band management access—Provide information about Routing Engine status to devices (console, laptop, or terminal server) that can be attached to access ports located on the Connector Interface Panel (CIP).

  Each Routing Engine has one 10/100-Mbps Ethernet port for connecting to a management network, and two asynchronous serial ports—one for connecting to a console and one for connecting to a modem or other auxiliary device.

• EEPROM—Stores the serial number of the Routing Engine.
• Reset button—Reboots the Routing Engine when pressed.

Note: The LEDs that report host module status (including Routing Engine status) are on the craft interface rather than the Routing Engine faceplate.

Note: For specific information about Routing Engine components (for example, the amount of DRAM), issue the show chassis routing-engine command.

Note: If two Routing Engines are installed, they must both be the same hardware version.

Tools and Parts Required

To replace a Routing Engine, you need the following tools and parts:

• Electrostatic bag or antistatic mat
• Electrostatic discharge (ESD) grounding wrist strap
• Phillips (+) screwdriver, number 2

Replacing a Routing Engine in an M320 or T320 Router, T640 or T1600 Routing Node, or TX Matrix Platform

This section describes how to replace a Routing Engine in an M320 or T320 router, a T640 or T1600 routing node, or a TX Matrix platform.

Replacing a Routing Engine

The Routing Engine is hot-pluggable. If the routing platform contains a redundant host subsystem, the Routing Engine and control board are hot-removable and hot-insertable. Before you replace a control board or a Routing Engine, you must take the host subsystem offline (see the hardware guide for your routing platform).

The routing platform 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 weighs approximately 2.4 lb (1.1 kg).

To remove a Routing Engine (see Figure 18 which shows the M320 routing platform):

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.
3. Check whether the Routing Engine is functioning as the backup or as the master. If necessary, take the host subsystem offline as described in the hardware guide for your routing platform.

   If the Routing Engines are configured for graceful switchover and are running a JUNOS release that supports 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.

   We recommend that you run JUNOS Release 7.0 or later on the M320 and T320 routers, and on the T640 routing node to support graceful switchover. We recommend that you run JUNOS Release 7.3 or later on the TX Matrix platform to support graceful switchover.

   Note: 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.

4. If applicable, loosen the screws on the extractor handles at either end of the Routing Engine faceplate, using a Phillips screwdriver.
5. Press the red tabs on the ejector handles on both sides of the Routing Engine faceplate.
6. Flip the ejector handles outward to unseat the Routing Engine.
7. Grasp the Routing Engine by the ejector handles and slide it about halfway out of the chassis.
8. Place one of your hands underneath the Routing Engine to support it and slide it completely out of the chassis.
9. Place the Routing Engine on the antistatic mat.
10. If you are not replacing the Routing Engine now, install a blank panel over the empty slot.

To install a Routing Engine (see Figure 19, which shows the M320 router):

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. Make sure the router is attached to a proper earth ground.
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, and 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. After the Routing Engine boots, verify that it is installed correctly by checking the RE0 and RE1 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 Routing Engine and Installing a 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

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

   For more information about using the CLI, see the JUNOS software manuals.