T320 Routing Engine Description
The Routing Engine is an Intel-based 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 router, control the router interfaces, control some chassis components, and provide the interface for system management and user access to the router.
You can install one or two Routing Engines in the router. 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 T-CB to be installed in the adjacent slot. RE0 installs below CB0, and RE1 installs above CB1. A Routing Engine does not power up without a T-CB present in the adjacent slot.
Each Routing Engine (shown in T320 RE-600 Description and T320 RE-1600 Description) consists of the following components:
- CPU—Runs JUNOS Software to maintain the router'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.
- CompactFlash card—Provides primary storage for software images, configuration files, and microcode. The drive is a fixed compact flask disk and is inaccessible from outside the router.
- Hard disk—Provides secondary storage for log files, memory dumps, and rebooting the system if the CompactFlash card fails.
- PC card slots—Accept a removable PC card, which stores software images for system upgrades.
- 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 model. |
