M320 Routing Engine Description

The Routing Engine runs the Junos operating system (OS). The 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. Each Routing Engine requires a CB to be installed in the adjacent slot. RE0 installs below CB0, and RE1 installs above CB1. A Routing Engine does not power up if a CB is not present in the adjacent slot.

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 can take over as the master. If the Routing Engines are configured for nonstop active routing, the backup Routing Engine automatically synchronizes its configuration and state with the master Routing Engine. Any update to the master Routing Engine state is replicated on the backup Routing Engine. If the backup Routing Engine assumes mastership, packet forwarding continues through the router without interruption. For more information about nonstop active routing, see the Junos OS High Availability Configuration Guide.

The master Routing Engine (if nonstop active routing is configured) and the backup Routing Engine are hot-removable and hot-insertable. A nonredundant Routing Engine or master Routing Engine (if nonstop active routing is not configured) is hot-pluggable.

The M320 router supports the following Routing Engines:

• RE-600-2048
• RE-1600-2048
• RE-A-2000-4096
• RE-A-1800x2 for Junos OS Release 10.4.