Advice on upgrading WLC with large number (4300-4400) of APs

[omz]

Hi all,

Looking for for some advice on upgrading a large number of access points appr. 4300-4400 access points associated to the WLC. 

I ll be doing the predownload on the APs.

Is the there a limit on the WLC on how many simultaneous connections it will allow?

How long can the whole upgrade process take?

Thanks 

[Scott Fella]

What code from to? What AP models?

[omz]

It’s a mix of APs 7xx 72xx and some others can’t remember on top of my head.

All models supported in the release notes. Upgrading to an escalation release suggested by TAC.

[Scott Fella]

I don’t know those AP’s. List the AP models and controller model and code version current and what you plan to use.

[omz]

AIR-CAP2602E-E-K9

AIR-CAP2602I-E-K9

AIR-CAP2702I-E-K9

from 8.0.152.0 to 8.0.152.8

 7500 controller

[Rasika Nayanajith]

Are you using "FlexConnect smart AP image upgrade" option ? If it is following need to be noted

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-4/config-guide/b_cg84/configuring_flexconnect_ap_upgrades_for_flexconnect_aps.html

A maximum of 3 slave APs of the same model can download the image from their master AP (a maximum of 3 TFTP connections can serve at a time). The rest of the slave APs use the random back-off timer to retry for the master AP to download the image. The random back-off value is more than 100 seconds. After a slave AP downloads the image, the AP informs the Cisco WLC about the completion of the download. After random back-off, the waiting slave AP can occupy the empty TFTP slot at the master AP.

Refer below for smart upgrade procedure

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-6/Flex_7500_DG.html#pgfId-43836

HTH

Rasika

*** Pls rate all useful responses ***

[Leo Laohoo]

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@omz wrote:

Is the there a limit on the WLC on how many simultaneous connections it will allow?

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Depends on the controller.  WiSM2 can do up to 500 APs.  5508 will do only 250.  8540 will do 1,000.  

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@omz wrote:

from 8.0.152.0 to 8.0.152.8

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Be aware that 8.5.152.8 is a special engineering release where the main was released October 2017.  

[Scott Fella]

It’s really hard to say how long it will take because you want to pre-download if possible and depends if the AP has enough space or not. Having FlexConnect groups can help depending if you have master setup like Rasika mentioned. Also I’m not a fan of “special versions”. If there is a newer version in which the issue is resolved, that’s what you should upgrade to. TAC should of provided guidance on that to be honest.

[omz · Accepted solution]

Update

-4 controllers and 4364 APs upgraded

- 'FlexConnect smart AP image upgrade' was not configured for all the groups - appr. 1500 APs

- uploaded the image to controllers 

- predownloaded image on the APs one controller at a time

- 1000 APs initiated the download 

- FlexConnect smart AP image upgrade - only master initiated the download 

- rebooted the controllers one by one

- time spent appr. 1.5 hours for each controller

I noticed that the APs with FlexConnect smart AP image upgrade took longer than the other APs. I guess - A maximum of 3 slave APs of the same model can download the image from their master AP (a maximum of 3 TFTP connections can serve at a time). - made it slower. To save WAN utilisation this would be the best approach. 

It took 7-10 mins for ~700+ out of ~1000 to complete the predownload, rest took like nearly an hour. First complete appearing in 3-4 mins.

Help

Upgrading the Controller Software

Configuring FlexConnect AP Upgrades for FlexConnect APs

- Enable session logging for Putty or similar 

- config paging disable/enable

- sh boot

- sh ap summary

- sh ap image all

- config ap image predownload primary all 

Scott, Rasika and Leo - Thanks guys!