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Cisco IOS XR Getting Started Guide
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Chapter3 Bringing Up the Cisco IOS XR Software on a Multishelf System
Restrictions
•ROMMON 1.40 or higher on each RP in the system
Caution The ROM Monitor software must be upgraded to version 1.42 or a later version on all RPs before a
Cisco CRS-1 system is upgraded to Cisco IOS XR Software Release 3.4.0 or a later release. If the router
is brought up with an incompatible version of the ROM Monitor software, then the st andby RP may fail
to boot. For instructions to overcome a boot block in the standby RP in a si ngle-chassis system, see
Cisco IOSXR ROM Monitor Guide. If a boot block occurs in a multishel f system, contact your
Cisco Systems support representative for assistance. See Obtaining Technical Assistance, page xiv.
In addition, Cisco CRS-1 multishelf systems should be upgraded to ROMMON release 1.40 before being
upgraded to Cisco IOS XR Release 3.4.0 to ensure that RPs are assigned the correct rack numbers during
system boot.
For more information, see Cisco IOS XR ROM Monitor Guide.

Hardware Requirements

Before you can bring up a multishelf system, the system components must be physically installed and
tested. Three multishelf system configurations are supported, and they require the following
components:
•Two 16-slot line card chassis containing eight FC/M (S13) fabric cards
•Two external Gigabit Ethernet Cisco Catalyst 6509 switches
Single-FCC systems require one FCC containing eight SFC (S2) fabric cards. Two-FCC systems require
two FCCs, and four-FCC systems require four FCCs. In two- and four-FCC configurations, the eight
SFC (S2) fabric cards are distributed equally in the FCCs.
For instructions to install, cable, and verify a multishelf system, see the documents listed on the
Cisco CRS-1 documentation web page listed in the “Related Documents” section on pagex.
Restrictions
The following restrictions apply to multishelf systems in Cisco IOS XR Soft ware Release 3.4.0.
•The multishelf system supports:
–
Two 16-slot line card chassis.
–
One, two, or four FCCs.
–
Two external Catalyst switches to form a control Ethernet plane used for administrative
management and monitoring of the system.
•The 4-slot and 8-slot LCCs are not supported.
•Although Cisco IOS XR Software Release 3.4.0 supports the addition of a second line card chassis,
the removal of a line card chassis is restricted. Consult your Cisco Systems support representative
for more information (see the “Obtaining Technical Assistance” section on page xiv).