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Cisco Catalyst 4500/4000 series switches display the %C4K_CHASSIS-3-UNKNOWNLINECARD error message when a new line card is installed


Core issue

The %C4K_CHASSIS-3-UNKNOWNLINECARD error message indicates that the module serial EEPROM has been read, and that the Field-Replaceable Unit (FRU) minor type is unknown. The current software image does not recognize this kind of module.


To resolve this issue, upgrade the software to a version that is compatible with the module or line card type. Refer to the Supported Hardware section of Release Notes for the Catalyst 4500 Series Switch, Cisco IOS 12.2EWx and 12.2 SGx.

Note: To upgrade the switch,  the user needs console access and the switch needs to be in ROM Monitor (ROMmon) mode.

If the supported software version is already installed, perform these steps:

  1. Re-seat the module.       
  2. Move the module to another slot or some spare Catalyst 4500/4000 switch, if available.        

For information about the linecards and the supported version, refer to Cisco Catalyst 4500 Series Line Cards Data Sheet.

For information about the upgrading the software when the switch is in the ROMmon mode, refer to the Recover from a Corrupt or Missing Image section of Recover a Cisco IOS Catalyst 4500/4000 Series Switch from a Corrupt or Missing Image or in Rommon Mode.

If these steps do not resolve the issue, refer to Cisco Technical Support.