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T4000 Routing Engine Description


The Routing Engine runs Junos 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 and 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 control board 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 control board 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 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 requires that you power down the router before replacement.


For specific information about Routing Engine components (for example, the amount of DRAM), issue the show chassis routing-engine command.

The ports for connecting the Routing Engine to external management devices are located on the Connector Interface Panel (CIP).

The T4000 router supports the Routing Engine in Table 1.

Table 1: T4000 Supported Routing Engines


Model Number

First Supported Junos OS Release





T4000 RE-C1800 Routing Engine Description

Note: These Routing Engines require the LCC-CB when a T4000 router is connected to a TX Matrix Plus router.