Arg! what is best IOS for 3650-8X24UQ ? seeing issues with 16.3.5b

[Rudy R.]

I replaced a 3560X with a 3650-8X24UQ and ARP is leaking on version 16.3.3  Looks like this bug:

https://quickview.cloudapps.cisco.com/quickview/bug/CSCun82902

So, I upgraded to 16.3.5b and half the devices stopped working...  only 369 MAC address came back.  I downgraded back to 16.3.3 and now see 770 MAC addresses via show mac address table.  Various IPs where not pinging/arping after the upgrade.

Any ideas?  I did the upgrade, reloaded, and didn't notice for an hour until complaints came.  Config didn't change, just IOS version.

[Reza Sharifi]

I would open a ticket with TAC and send the info. It may be an unknown issue to them.

HTH

[Leo Laohoo]

Hold on ... I just checked the Cisco website and there is no such thing as a "16.3.5b".  What is there is the Denali version. 

Word of warning, if there is an IOS that starts with the words like "Denali", "Fuji", "Everest" ... It means the IOS is an open BETA (or open-beta "like").  

The only version for the 3650-8X24UQ that isn't an open-beta is 16.2.X and it's deferred.  

Personally, I've never had a good experience with 16.X (open beta and regular) and I try to avoid it like a rash.  

But Reza is correct, raise a Cisco TAC Case and get them to analyze it.  

[Rudy R.]

OK, emailing cisco!

Anyone force a 3.7.5 onto a 3650-8X24UQ?  I may try it in the office and see what happens!

Rudy

[Leo Laohoo]

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@Rudy Rucker wrote:

Anyone force a 3.7.5 onto a 3650-8X24UQ?

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Don't do that Rudy.  The switch will go into ROMmon.  

You have no choice.  TAC may be able to spin up a fixed code (emphasis on the phrase "may be").

[Rudy R.]

Seems like I have to continue with the open beta program swearing-like-a-sailor-kicking-and-screaming, sigh.  ;)

If anyone has tried 3.7.5 on this model, let me know.

(PS, in all the excitement of getting a 4x 10Gbps switch up today, I accidentally looped another switch with a 1Gbps and new 10Gbps fiber - STP didn't kick in properly and the Cisco 3650 switch promptly crashed and rebooted.  I caught an earful from that incident.  I hope 16.3.3 is put to bed soon!)

[Rudy R.]

The issue with mac addresses disappearing was due to the native vlan getting pruned on trunking ports. Other versions of IOS did not prune the native VLAN so aggressively. ¯\_(ツ)_/¯

To see the state of your trunks and what is pruned, use the 'show interfaces pruning'.  You can disable pruning per interface with the following command

switchport trunk pruning vlan none

 or you can turn off pruning in your VTP domain controller.

This switch has been up for 17 weeks on 16.6.2.

(Still seeing ARP leaks when two ports are 'switchport protected')