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 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
Issue the show modulecommand 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.