cisco 3850 show command crashes switch + ACL hardware counters

[paul amaral]

Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 16 WS-C3850-12XS 16.9.4 CAT3K_CAA-UNIVERSALK9 BUNDLE

while trying to figure out how to show hardware counters for specific ACLs, I ran into a hardware crash issuing the following command.

sh platform hardware fed switch active fwd-asic resource tcam utilization 3 where 3 is an ASIC that doesn't exist.

If you issue the above command with an asic id that does not exist, the router will crash with the following error

System returned to ROM by Critical process fed fault on fp_0_0 (rc=134) at 01:26:45 EST Sat Feb 8 2020

System image file is "flash:cat3k_caa-universalk9.16.09.04.SPA.bin"

Last reload reason: Critical process fed fault on fp_0_0 (rc=134)

I tested this on a 3650 and there is not issue, same IOS

Switch-#$ active fwd-asic resource tcam utilization 3
Invalid Asic No: 3

I know alot of the platform commands on this switch don't work like they do on other XE IOS like the ASR due to hardware but it's troubling to know that this show command brought down the switch, especially on a gold image. Also there seems to be a lot of command changes from 3.X to 16.X but even within 16.x the commands change from doc to doc. 

I was trying to see ACL hit counter information for specific ACL on the catalyst 3850 IOS 16.9.4, the doc referrence command, sh platform acl counters hardware which doesn't work on 16.9.x. Does anyone know how to view hits stats for specific ACLs?

Paul 

[Georg Pauwen]

Hello,

check if the bug below applies. The 9200 is listed as affected device, but the 3850 might as well, as these bugs are not always correctly updated. You could try and upgrade to one of the recommended fixed releases...

system crash on execute "fed TCAM utilization"
CSCvr07162
Description
Symptom:
A Catalyst 9200 switch may crash when executing "show platform hardware fed switch active fwd-asic resource tcam utilization 1".

Conditions:
The issue was not reproduced.The fix was given based on trace decode.
But the issue was seen when the system coming up and the system was not initialised properly.At the time if show cli is executed, due to failure, code goes to error code, due to double free of buffer used for show cli , the system crashed.

Workaround:
Don't execute the cli while the system coming up.

Known Fixed Releases: (10)
17.1.1
16.12.2
Amsterdam-17.1.1
17.2(0.46)
17.1.1a
17.1(0.72)
16.12.2s
16.12.2a

[paul amaral]

Maybe I'm hitting that bug on the 3850 but the interesting thing is on the 3650 with the same IOS it doesn't happen. I notice that alot of platform hardware commands do not work correctly on the 3850, mostly because of the unified IOS and the different in asic/hardware from devices that share the same IOS. I was just a little troubled by the fact that 16.9.4 is a gold star IOS and then i crash my switch in the middle of the day using a show command :(.

I also can't figure out how to see hardware ACL counters, there doesn't seem to be a way on the 3850.

Paul