The Routing Engine is an Intel-based PCI platform that runs JUNOS Internet 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.
Figure 20: Routing Engine 1600
Figure 21: Routing Engine 2000
Each Routing Engine (shown in Figure 20 and Figure 21) consists of the following components:
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.
Note: The LEDs that report host module status (and 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.
To replace a Routing Engine, you need the following tools and parts:
This section describes how to replace a Routing Engine in an M320 or T320 router, a T640 routing node, or a TX Matrix platform.
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 CB 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 22 which shows the M320 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 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 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.
Figure 22: Removing a Routing Engine
To install a Routing Engine (see Figure 23, which shows the M320 router):
The Routing Engine might require several minutes to boot.
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.
Figure 23: Installing a Routing Engine