3850 Switch Stacking

[abe_alawy]

Hello everyone,

I was wondering if someone can help me out. I have recently purchased 12 Cisco 3850 switches but I am having an issue stacking them. I can only get 4 to stack but according to Cisco you can stack up to 9 I believe. I am running IOS 3.3.05SE which is the recommended version to have. Anyone else have this issue or can help out?

[scotty.hunter]

Hey man,

After a little digging, I found this article on the Cisco website:

http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3850-series-switches/qa_c67-722110.html

Under License and Warrantee, question 10 states, "Stack member addition example: A Cisco Catalyst 3850 stack with 3 switches, each with an access point count license of 10 access points, will have support for a total of 30 access points. When a new Cisco Catalyst 3850 (Switch 4) is added to the stack with an access point count license of 25 access points, the total access points supported by the stack equals 50, since the total (30+25) 55 exceeds the stack limit."

Hopefully that at least points you in the right direction!

-Scotty

[abe_alawy]

Hi Scotty,

Thanks for replying. I read that article before and actually read that same question and answer. But it only talks about adding the AP's and licenses. I wish somewhere in that article it says how you stack beyond the 4th switch. Nevertheless, thank you for answering. It's been driving me crazy for the past few week.

[scotty.hunter]

Disregard what I posted, I should of dug a little deeper. jhager001 in the new comment found the info.  I apologize for the misinformation, looks like there is still hope!

[abe_alawy]

Hi Scotty,

Still working on the issue, no solution yet.

[scotty.hunter]

I'm sure you already know/have seen this, but I found another article showing the cabling for both the stackwise cables and the stackwise power cables. 

https://supportforums.cisco.com/document/12575126/how-form-catalyst-3850-data-stack-and-power-stack

Since you said that they are all running the same IOS, you shouldn't get any version mismatch issues, perhaps one of the stackwise ports is messed up? Try powering them down and take the switch that it stops at and move that one to the top of the stack and see if it stops at the same place.

[abe_alawy]

Hi Scotty, ,

I really want to thank you for all your help. Just figured out the cause of the issue literally 5 minutes ago. It turns out 3 of the stackwise cables had at least one bad end. I failed to do a show switch stack-ports to verify that there was end to end connectivity. To be honest I have never had this issue before so it didn't cross my mind. Lesson learned and noted. 

So again thank you.

[scotty.hunter]

Right on, I glad I was able to help!  I haven't run into an issue like that either.  Just another tool for the toolbox!

[jhager001]

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/ha_stack_manager/configuration_guide/b_hastck_3se_3850_cg/b_hastck_3se_3850_cg_chapter_010.html#concept_9A3E00DDAC484E3486A09561B91D7CAB

StackPower only allows up to 4 switches.

480-StackWise cables allow up to 9 switches.

Make sure your stacking cable pattern is correct between the switches.

[abe_alawy]

Hi Jhager001,

Thanks for the info. I tried everything and triple checked the stacking pattern but I am still running into the same issue. It will only stack the 4 switches. I originally had 7 switches that I wanted to put in a stack, the first 4 switches would make a stack and then the last 3 switches would make their own stack. I tried different stackwise cables just to make sure the one between the 4th and 5th one was not bad but no dice. I am only using the stackwise cables no stack power, but I don't think that would make any difference. All switches have the same IOS version and all are running in install mode. I have the master switch with a priority of 15 and the rest are just the default 1. Master switch is also provisioned 1-7. Not sure if I'm missing anything else.

[jhager001]

what does your 'show switch' output look like? does it even see them in the stack?

[abe_alawy]

Hi Jhager,

Thanks for helping me with this issue. You can see from my response to Scotty that the issue was bad stackwise cables. The show sw output initially showed 1-4 as active but would not connect that 5th switch. I happy to say that I have 6 switches in the stack now and will be adding the 7th and 8th as soon as I can get more and longer stackwise cables.

I appreciate you helping me with this issue.

[jhager001]

Glad to be of some help, and that you figured out the cause of the issue!