upgrading from 3.6.6E to 16.12.5 MD help

[baselzind]

i have 3650 switches that need to be upgraded from 3.6.6E to 16.12.5 MD. Can i upgrade directly through booting from the new image? also do i need to update the ROM version?

the document below mention it is possible but just need to make sure

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/16-12/release_notes/ol-16-12-3650.html

[balaji.bandi]

The Microcode automatically upgrades, so you need more maintenance window to compare to normal, its microcode upgrade then IOS Upgrade.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/16-12/release_notes/ol-16-12-3650.html#task_k3s_tgq_k3b

On the side note: new version 16.12.X required smart License  (Look at the above document -(License Levels - Usage Guidelines)

[baselzind]

thanks but what about the ROM version? does it need to be upgraded as well?

[balaji.bandi]

As I mentioned that will automatically upgrade part of the upgrade process.

1. make sure you read the release notes and understand the caveats.

2. take the configuration out of the box before the upgrade.

3. do the upgrade in the maintenance window, since the switch required to reboot to take effect new IOS.

[baselzind]

isn't the smart licensing only expiration effect is log messages? or the switch would stop working?

[Leo Laohoo]

---

@baselzind wrote:

or the switch would stop working?

---

Nothing will happen.

[balaji.bandi]

Switch will work as expected, but License mode change from traditional to smart (so make aware to register device with smart License Server)

[Leo Laohoo]

---

@baselzind wrote:

i have 3650 switches that need to be upgraded from 3.6.6E to 16.12.5 MD.

---

Does the switch/stack use PoE?  If it does, then be careful of hitting CSCvv54912

[baselzind]

yeah, it is in stack , but I read in the bug report it is fixed in 16.12.5? correct?

[balaji.bandi]

yes as per the release notes it's fixed in 16.12.5, but make sure you aware. in case if you hit with the same issue.

[Leo Laohoo]

---

@baselzind wrote:

yeah, it is in stack

---

Does the switch provide PoE?  There is another SNMP/PoE "combo" bug which was first reported in 16.12.1 and have never been fixed in 16.12.4.  
The bug will appear between 4 to 12 weeks uptime. 

---

@baselzind wrote:

I read in the bug report it is fixed in 16.12.5? correct?

---

A lot of Bug IDs contain inaccurate information.

[baselzind]

thanks for the info , what is this snmp/poe bug? please link it . So I shouldn't upgrade? is it too risky?

[Leo Laohoo]

---

@baselzind wrote:

thanks for the info , what is this snmp/poe bug? please link it . So I shouldn't upgrade? is it too risky?

---

I was too busy at the office today so I was unable to dig out the SNMP/PoE bug. 

You need to upgrade.  There is no question about it.  The firmware you are running is old.  The question is to which version. 

The latest 3.6.X is a safe version.  It may be EoS already but some of the bugs do not keep me up, screaming, all night.  

Alternatively, the latest 16.3.X and 16.6.X are also not bad.  

[Leo Laohoo]

Have a look at CSCvt70277 & CSCvf33653.

[Leo Laohoo]

---

@baselzind wrote:

thanks for the info , what is this snmp/poe bug? please link it . So I shouldn't upgrade? is it too risky?

---

PoE/SNMP Bug ID is CSCvv28324.

Depending on what 16.12.X firmware the switch is running, there is an SMU patch (cat3k_caa-universalk9.16.12.04.CSCvv28324.SPA.smu.bin) that is meant to fix the issue, however, I have several stacks with the SMU applied and the PoE bug shows up around 4- to 8 weeks uptime. 

The only known "workaround" is to regularly reboot the stack.