Routing Engine

The Routing Engine provides three main functions:

• Creates the packet forwarding switch fabric for the Services Router, providing route lookup, filtering, and switching on incoming data packets, then directing outbound packets to the appropriate interface for transmission to the network.
• Maintains the routing tables used by the router and controls the routing protocols that run on the router.
• Provides control and monitoring functions for the router, including controlling power and monitoring system status.

The Routing Engine consists of the following components:

• Processor—Creates the packet forwarding switch fabric for the router and runs JUNOS Internet software to maintain the router's routing tables and routing protocols.
• DRAM—Buffers incoming packets and provides storage for the routing and forwarding tables and for other Routing Engine processes.

  To view the amount of DRAM installed on your router, issue the show chassis routing-engine command.

• EPROM—Stores the serial number of the Routing Engine.

  To view the serial number of the Routing Engine, issue either the show chassis routing-engine command or the show chassis hardware command.

• Crypto Accelerator Module—Processor card that enhances performance of cryptographic algorithms used in IP security (IPSec) services. The cryptographic algorithms supported include Advanced Encryption Standard (AES), Data Encryption Standard (DES), triple DES (3DES), Hashed Message Authentication Code-Message Digest 5 (HMAC-MD5), and HMAC-Secure Hash Algorithm 1 (SHA-1). The Crypto Module is a standard feature of J6350 Services Routers and an optional feature of J4350 Services Routers.

  To determine whether there is a Crypto Accelerator Module installed on your router, issue the show chassis hardware command.

• Compact flash drive—Provides primary storage for software images, configuration files, and microcode. J4350 and J6350 routers have an internal compact flash drive, located on the motherboard. For information about replacing the compact flash drive, see Replacing the Compact Flash Disk.

Boot Devices

The J4350 and J6350 Services Routers can boot from two devices:

• Compact flash disk
• USB storage device

Normally, the Services Router boots from the compact flash disk. If the compact flash disk fails, the router attempts to boot from the USB storage device.