M10i Routing Engine 850 Description
Figure 1: Routing Engine
The Routing Engine 850 has the following major components (see Figure 1):
- CPU—Runs Junos OS to maintain the router's routing tables and routing protocols. It has a Pentium-class processor.
- SDRAM—Provides storage for the routing and forwarding tables and for other Routing Engine processes.
- CompactFlash card—Provides primary storage. It holds software images, configuration files, and microcode.
- Hard disk—Provides secondary storage for log files and memory dumps, and can reboot the system if the CompactFlash card fails.
- I2C/EEPROM—Stores the serial number of the Routing Engine.
 | Note: For specific information about Routing Engine components (for example, the capacity of the hard drive), issue the show chassis routing-engine command. |
The faceplate of the Routing Engine 850 contains the following:
- PC card slot—Accepts a removable PC card, which stores software images for system upgrades.
- 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 Routing Engine.
- Reset button—Reboots the Routing Engine when pressed.
- Offline button—Powers down the Routing Engine when pressed.
- Thumbscrews—Secure the Routing Engine in the chassis.
- Four LEDs—A green LED labeled HDD, a blue LED labeled MASTER, a red LED labeled FAIL, and a green LED labeled ONLINE indicate Routing Engine status.
The disk from which the router boots is called the primary boot device, and the other disk is the alternate boot device.
The boot sequence for the router:
- PC Card
- CompactFlash card
- Hard disk
| Note: If the router boots from an alternate boot device, a yellow alarm lights the LED on the router’s craft interface. |
