Juniper Networks M160 manual Routing Engine

Hardware Component Overview

For host module replacement instructions, see “Replacing an MCS” on page 159 and “Replacing a Routing Engine” on page 165.

Note that the effect of a hardware or software failure on one or both components in the master host module differs from the effect of removing a component that belongs to the master host module:

With the default router configuration, in case of failure you must correct the problem manually. You can issue the appropriate

request chassis routing-engine master command to switch mastership to the other Routing Engine, for example. For information about the command, see the JUNOS Internet Software Operational Mode Command Reference: Protocols, Class of Service, Chassis, and Management.

On routers with two installed Routing Engines running JUNOS Release

6.0or later, you can configure graceful switchover of Routing Engines, as previously described for the case of Routing Engine removal. When the standby Routing Engine stops receiving keepalive signals from the master Routing Engine, it automatically assumes mastership without interruption of forwarding performance.

On routers with two installed Routing Engines running any JUNOS release, you can configure automatic Routing Engine mastership failover. When the standby Routing Engine stops receiving keepalive signals from the master Routing Engine, it automatically assumes mastership. Packet forwarding halts while the Packet Forwarding Engine components reset and connect to the new master Routing Engine.

For information about configuring graceful switchover or automatic mastership failover, see the section about Routing Engine redundancy in the JUNOS Internet Software Configuration Guide: Getting Started.

For more information about host module components, see the following sections:

Routing Engine on page 23

Miscellaneous Control Subsystem (MCS) on page 25

Routing Engine

The Routing Engine is an Intel-based PCI platform that runs JUNOS Internet software. Software processes that run on the Routing Engine maintain the routing tables, manage the routing protocols used on the router, control the router’s interfaces, control some chassis components, and provide the interface for system management and user access to the router.

For a description of the Routing Engine’s role in router architecture, see Routing Engine Architecture on page 53.

One or two host modules (paired Routing Engine and MCS) can be installed into the midplane from the rear of the chassis, as shown in Figure 3. If two host modules are installed, the Routing Engines together determine which is

Host Module 23