Cisco 12000 Series Routers

Field Notice: Illegal MBUS Group Type Messages on Some 12016 and 12410 MBUS Controllers

Updated December 18, 2001

August 30, 2000

Products Affected

  • 12016 Alarm Cards

  • 12016 Power Supply Busboard

  • 12410 Alarm Card

Problem Description

Maintenance Bus (MBUS) agent code versions 2.03 and lower reprogram the MBUS ID EEPROM group ID of any board shipped with an ID above 07. An upgrade to a later Cisco IOS® Software Release or MBUS agent code could then result in a mismatch between the actual group ID and the expected group ID on these MBUS controllers. This mismatch will result in a warning message.

Note:?The warning message is benign and does not affect router operation.


MBUS IDs are internal operating system parameters which have no real importance to the user, nor are they user configurable. There is no straightforward set of commands the user can issue to view MBUS Group Type ID values. In the initial design of the GSR platform, it was believed that there would not be more than seven MBUS group types and that the MBUS group ID could never be greater than 7. This is no longer true with the newer GSR systems.

The earlier versions of the MBUS agent code were written with the expectation that the highest group ID of a board would be 7. There are circumstances where an early version of MBUS agent code will reprogram the ID EEPROM chip of a board from some higher value and rewrite it to 7. This rewrite does not cause any immediate issue, but it can result in a warning message for that controller with the next Cisco IOS Software upgrade.

This situation exists only with MBUS agents earlier than version 2.03.

Problem Symptoms

Affected devices will generate messages similar to these.

WARNING: Illegal MBUS group type 7 in slot 24 
Contact your technical support representative.
WARNING: Illegal MBUS group type 7 in slot 25 
Contact your technical support representative.
WARNING: Illegal MBUS group type 7 in slot 27 
Contact your technical support representative.

Note:?Slots 24 and 25 correspond to the two alarm cards. Slot 27 corresponds to the router's busboard, which is a printed circuit board interconnecting the router's power supplies.


This issue is purely cosmetic and it is safe to run the system with this message displayed. No workaround is required. If one is desired, the following items provide possible actions to take to remove the warning message.

  • If the system is running Cisco IOS Software Version 12.0(17)S or later, execute the upgrade-mbus-agent-rom command from the affected card.

  • If the system is running an earlier Cisco IOS Software Release, upgrade to Cisco IOS Software Release 12.0(17)S or later and then execute the upgrade-mbus-agent-rom command.

  • If the system is not running, or unable to upgrade to Cisco IOS Software Release 12.0(17)S, it is possible to load a special boot image which will correct the incorrect group type IDs. This method requires that the router must be taken out of service to complete. Please contact the TAC to obtain this boot image and for assistance.

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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