Core issue
The interprocess communication (IPC) errors generally indicate that both supervisors run different Cisco IOS software releases or have incorrect boot variable information. This does not always cause operational failure.
In some scenarios, these messages appear when these are not synchronized between both the supervisors:
- the configuration
- the boot variable
- the configuration register
- the Virtual LAN (VLAN) database
Along with the IPC errors, the show boot command can display these error messages:
- Standby BOOT variable is unobtainable due to IPC error
- Standby CONFIG_FILE variable is unobtainable due to IPC error
- Standby BOOTLDR variable is unobtainable due to IPC error
- Standby Configuration register is unobtainable due to IPC error
Resolution
Issue the show module command in order to see if both supervisors run the same Cisco IOS software release. If they run different Cisco IOS software releases, upgrade or downgrade the slave supervisor in order to match.
If both supervisors run the same Cisco IOS software release, as a workaround, re-seat the passive supervisor so that it synchronizes the information.
