Cisco WAN Switching Modules

Field Notice 980105: ASC2 May Fail to Boot Up Gracefully

January 13, 1999

Products Affected




The AXIS Shelf Controller 2 (ASC2) is the second generation ASC.

Problem Description

The ASC2 may fail to boot up properly after a shelf power cycle, ASC2 insertion, switchcc command, or resetsys command. The customer impact for an MGX-8220 shelf with redundant ASC2s is that the ASC2 redundancy is disabled. The customer impact for MGX-8220 shelves with a single ASC2 is that all traffic through the shelf is interrupted until the ASC2 is recovered. (See the "Workaround" section below for recovery instructions.)


This problem results when the ASC2 boots up and and attempts to synchronize with the backplane cellbus. If the ASC2 attempts to switch between cellbuses during boot-up, this failure may result.

This problem occurs less than once in five power cycles or switchcc commands.

Problem Symptoms

When this problem occurs, all three LEDs are on and dspcds shows that the card failed.

The log shows "Cell Bus Fail". Use the dsplog command to observe the event log.


Workaround: Until the firmware 4.0.19 (or later) is installed, the failed ASC2 may be recovered by resetting the card (use the resetcd command) or physically reseating the card.

Solution: MGX-8220 firmware version 4.0.19 resolves this issue. Customers are urged to upgrade to 4.0.19 or later to prevent this ASC2 failure.


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



View CSCdk09893

ASC2 fails on switchcc.

View CSCdk51836

ASC2 failed state after power cycles or switchcc.

How To Upgrade Software

Upgrade techniques for the ASC2 are located on Cisco's web site. Click here to access the "ASC and Service Module Firmware and Backup Boot Code Upgrade and Downgrade Techniques" Technical Tip.

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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