M160 Internet Router Hardware Guide
the master and which is in standby mode (andso performs no functions). By
default, the RoutingEngine in the slot labeled RE0 is the master. The master
Routing Engine also determineswhich of the two PCGs is the master.
The Routing Engine is hot-pluggable, as described i n Field-Replaceable
Units (FRUs) on page 4. For information about the e ffect of removing a
Routing Engine, see Host Module on page 22. For replacement instructions,
see “Replacing a Routing Engine” on page165.
Routing Engine Components
TheRoutingEngine(showninFigure9)isatwo-boardsystem
with the following components:
CPU—Runs JUNOS Internet softwareto maintain the router’s routing tables
and routing protocols. It has a Pentium-classprocessor.
SDRAM—Provides storagefor the routing and forwarding tables and for other
Routing Engine processes.
Compact flash drive—Providesprimary storage for software images,
configuration files, and microcode. The drive is fixed and inaccessible from
outside the router.
Hard disk—Provides secondary storage for log files, mem ory dumps, and
rebooting the systemif the flash drive fails.
PCcardslots—AcceptremovablePCcards,whichstoresoftwareimages
for system upgrades.
LED—Indicates disk activity for the internalIDE interface. It does not
necessarily indicate routing-relatedactivity.
Interfaces for out-of-bandmanagement access—Provide information about
Routing Engine status todevices (console, laptop, or terminal server) that can
be attached to accessports located on the Connector Interface Panel (CIP).
EEPROM—Stores the serial numberof the Routing Engine.
Reset button—Rebo ots the Routing Engine when p ressed.
NOTE: The LEDs that report hostmodule status (and by implication Routing Engine
status) are on the craft interface rather than the Rou ting Engine faceplate. For more
information, see “Host Module LEDs”on page 31.
NOTE: The appearance and position of electroniccomponents or the PC card
slot on your Routing Enginemight differ from Figure 9 and other figures in this
24 Host Module