alternate number (828)-505-7480

We ran into an issue where a Cisco 3850 switch (3850-12X48U) lost the ability to use the its C3850-NM-8-10G network module after a firmware upgrade.  The module had been working for a few years prior to the upgrade.  We upgraded from 16.03.07 to 16.12.05 and upon booting we saw messages such as:

*** Uplink FRU module hardware authentication failed. ***

and

%PLATFORM_PM-6-FRULINK_UNKNOWN_INSERTED: Unsupported FRU module inserted in slot 1

When we ran “show inventory” the module was not listed.  We then downgraded back to the old version and we received the same messages!  We had a few other identical network modules, so we swapped them but the problem persisted.  A module that ultimately worked was the C9300-NM-8X which is a 9300 switch module, but it appears identical to the C3850-NM-8-10G.  I have ordered more of these to keep as spares in case this happens again!

The following Cisco bug seems to line up with my experience: https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvd86925/  Even though the bug claims the problem is fixed in 16.3.X and above, however I can confirm this is not the case.