Cisco 12000 Series Routers

Field Notice: Cisco 12000 Routers May Fail to Boot from an ATA Disk During Upgrades to Cisco IOS Software Release 12.0(22)S.

July 23, 2002

Products Affected

  • Cisco 12000 Series

Problem Description

An enhanced version of the ROM Monitor (ROMMON v. 182) is bundled into Cisco IOS® Software Release 12.0(22)S to support direct Cisco IOS software boot from ATA PC Cards (Flash disks). This ROMMON version 182 requires the PC ATA cards to be formatted by Cisco IOS Software Release 12.0(22)S or later before they can be read by Cisco 12000 series routers.

Note: Disks formatted by Cisco IOS software releases earlier than 12.0(22)S cannot be read.

Users who upgrade their Cisco IOS Software to release 12.0(22)S should format any ATA PC cards as soon as possible to avoid any operational disruption.


When a router is booted from a 64-MB or 128-MB ATA disk PCMCIA card, the error string monlib does not contain a valid magic number will be displayed. The router will then return to the ROM monitor (rommon) prompt. This occurs because the flash disk is still formatted with Cisco IOS Software Release 12.0(21)S or earlier, and the new rommon version 182 cannot read a 12.0(22)S format.

PCMCIA cards of other capacities (including linear Flash PCMCIA cards) have not been observed to exhibit this problem.

Using the service upgrade all command will force the upgrade of fab loaders and line card rommons. It will not force the upgrade of the GRP rommon. Given the destructive nature of GRP rommon upgrade, the upgrade must be done manually. A warning is generated after using the service upgrade all command, which requires the user to confirm the upgrade.\


CML-QDOME#up rom
Upgrading grp rom in slot 5
The current revision of GRP ROM is: 181
The new revision of GRP ROM will be: 182
Please note: GRP ROM upgrade typically takes 30 to 240 seconds. After GRP 
ROM upgrade the GRP will be reset.
Continue GRP ROM upgrade? [yes/no]: yes
Starting GRP ROM upgrade ...

Problem Symptoms

When attempting to upgrade a Cisco 12000 series router to Cisco IOS Software Release 12.0(22)S from an ATA disk, the router does not boot.


This problem can be avoided prior to software upgrade. The following measures have been tested and work:

  1. Use a linear Flash PCMCIA card.

  2. When using an ATA disk, specify boot system flash disk0:[image] in the startup configuration prior to upgrade.

  3. When using an ATA disk, specify the "flash" keyword on the rommon prompt boot flash disk0:[image].

  4. Prior to upgrade, reformat the ATA disk from its current Cisco IOS Software Release.


To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.




Router may fail to boot from a ATA disk

Cisco IOS Versions Affected

These Cisco IOS Software versions for the Cisco 12000 series are affected:

  • gsr-p-mz.120-22.S.bin

  • gsr-boot-mz.120-22.S.bin

  • gsr-k4p-mz.120-22.S.bin

  • gsr-k3p-mz.120-22.S.bin

Release Note

For additional information about known problems in Cisc IOS Software Release 12.0(22)S, refer to the 12.0S IOS Release Notes.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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