CHAPTER 4
Host Subsystem Components and
Descriptions
MX104 Routing Engine Overview
Copyright © 2017, Juniper Networks, Inc.
MX104 Routing Engine Overview on page 27
Routing Engine Specifications on page 30
Supported Routing Engines by Router on page 33
The Routing Engine is a Freescale-based PC platform that runs Junos OS. 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 Engine installs into
the front of the chassis. Two USB ports on the Routing Engine accept a USB memory
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. The backup Routing Engine is
The MX104 router supports the Routing Engine with model number RE-MX104.
Figure 11: MX104 Routing Engine
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