Cisco IGX 8400 Series Switches

CSCdz48594 ALM/B Firmware may result in dropped user data in IGX8430 systems. Field Notice

March 27, 2003

Products Affected




Installed in IGX 8430 slot 17 through 32 with firmware revisions C.B.K. or C.B.L.

Problem Description

Customers may experience COMM FAIL errors. In addition, customers may experience egress discards on Foresight connections transiting the ALM/B. This anomaly is not dependent on any release of IGX software and is tied specifically to ALM/B firmware. In addition, ALM/A are not affected by this anomally.


This anomaly may occur when the following conditions are present:

  • ALM is in trunking mode, that is, programmed as an ALM/B.

  • ALM firmware load is either C.B.K or C.B.L.

  • ALM/B must be installed in lower shelf of IGX 8430*

Note:? *The IGX 8410 and IGX 8420 are not affected by this anomally.

Problem Symptoms

Network Maintenance Engineers may notice logging of COMM FAIL messages in the event log. These may be viewed by using the command dsplog. In addition, Egress Discards my be observed on connections traversing the affected ALM/B trunk. Use the command dspchstats slot.port.DLCI on a connection that traverses the suspect ALM/B to observe the discards.


As a workaround, if possible, reroute around ALM/B trunks. The solution is to load ALM/B firmware C.B.H.


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



CSCdz48594 (registered customers only)

ALM/B has com failure

CSCdw45112 (registered customers only)

Egress discards on fst connection running over ALM

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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