ISR4321 Switch Module Not Working – CPLD Incompatibility

I recently had the pleasure of upgrading a ISR4321 router to Denali (16.3.5). If you have a NIM-ES2-8 for example you might want to be careful and check the CPLD version before doing the upgrade! Here is why.

Here the CPLD version is 14101324

The Firmware Version is the ROMMON version.

As of writing there is no way of correlating the CPLD version show in the output of show platform and the one you can download on CCO. And for ISR4321 there is only one version on CCO.

Why is this important? Well, if you upgrade to Denali this will show up in the log after the upgrade:

*Jan 17 2018 10:07:34.633 CET: %SPA_OIR-3-RECOVERY_RELOAD: subslot 0/1: Attempting recovery by reloading SPA
*Jan 17 2018 10:07:34.637 CET: %SPA_OIR-6-OFFLINECARD: SPA (NIM-ES2-8) offline in subslot 0/1

Router#sh hw-module subslot 0/1 oir
Module        Model                Operational Status
------------- -------------------- ------------------------
subslot 0/1   NIM-ES2-8            out of service(failed too many times)

After you upgrade the CPLD version the module will work again.

Router#show hw-module subslot 0/1 oir
Module        Model                Operational Status
------------- -------------------- ------------------------
subslot 0/1   NIM-ES2-8            ok

And as of writing this was not documented in the release notes or anywhere else in Cisco Documentation!