Cisco Catalyst 9800-40 Wireless Controller

[lachimip]

Hi all,

I am new to Cisco WLC.

I have Cisco Catalyst 9800-40 Wireless Controller and it is running on software version 17.3.4c.

I am told to upgrade to the latest one and I have no idea which is the latest one with no bug in it. I tried to download the software from website, but I saw many different types and I am bit worried that I may use the wrong one. I am attaching here the to show which made me more confused. Can anyone tell me which is the latest and bug-free firmware for my controller( Cisco Catalyst 9800-40 Wireless Controller) and send me a link to download it. I can only upgrade it from GUI if you would like to show me some steps as well.

[Leo Laohoo · Accepted solution]

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@marce1000 wrote:
the wireless must always be there  , also at night (e.g.)

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That is highly debateable and subjective.  Most 9-5 business do not want to implement nightly reboot because they do not know how to automate this.  And most "24-hour" business do not know when they can have a 6 minute WiFi outage.  

Option B:  Do not use 17.9.4/17.9.4a or 17.9.5. 

Option C:  Do nothing and tolerate a rolling outage when the bugs (plural term) kick in.

[Leo Laohoo]

@lachimip, @marce1000, @eglinsky2012,

We have been told by WNBU to keep the controller AP capacity to <85%, i.  e.  <5000 x APs for the -80 and <850 x APs for the -40. 

I personally believe HA SSO is a very bad solution because HA SSO contributes to the instability of the WLC.  For instance, we have 2 x 9800-80 in HA SSO and 2 x 9800-80 in standalone and the HA SSO constantly needs to be failed-over.  The most common issue we've seen is the controller would randomly put users in "Authenticating" state.  Failover would temporarily fix this issue until it re-occurs again.

I think daily reboot of the APs is going to be a "norm".

[Rich R]

> We have been told by WNBU to keep the controller AP capacity to <85%, i.  e.  <5000 x APs for the -80 and <850 x APs for the -40. 
Is there a bug/bugs for that @Leo Laohoo ?  What's the explanation for the issue?

[Leo Laohoo]

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@Rich R wrote:
Is there a bug/bugs for that @Leo Laohoo ?  What's the explanation for the issue?

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No explanation provided but, personally, suspect it has something to do with WNCD, aka "load balancers".

Currently, with our TAC cases involving 17.9.4/17.9.4a & 17.9.5, the load balancers have divided the APs and users "equally" what they are having problems with is when the clients are roaming between "load balancers".   When I told our TAC engineers about what WNBU told us (about the number of APs), they kept quiet and did not contradict.  

EDIT: 

Not sure about this, but I think it is related to CSCwj33979.

[p.lan]

For what its worth (and to help you save any hairs remaining)...

17.9.3 with all SMUs and APSP6 applied has been our most rock solid deployment of 9800 wireless, to-date. No crashes, no random HA failovers. ~1500 APs consisting of 3800/9120/9130/9136/9164 APs are all functioning solid on 9800-40. ~18k clients daily and ~8gbps of average throughput in a day. Maybe a random crash here and there on a single, random AP... maybe once a week, but well within our tolerances.

I have other customers on 17.9.4a, 17.9.5 experiencing random issues. Not to mention ISSU bounced all APs at once going from 17.9.3 to 17.9.5 due to incorrect SUDI cert being selected on the new active unit after switchover. I'm keeping our largest customers on the magic 17.9.3 combo until something forces them onto newer code... likely a new AP model or something. 

[marce1000]

 -  Go for https://software.cisco.com/download/home/286316412/type/282046477/release/Cupertino-17.9.5
     which is current advisory release. 
                   >...I have no idea which is the latest one with no bug in it. I 
     In the modern complex world, that is 'no longer possible'  , 

 M.

[Rich R]

1. There is no release which has no bugs, they all have bugs, it's a matter of choosing one that seems to have fewer bugs, and testing it for your setup.  Review the release notes carefully for any warnings etc.

2. In general refer to the TAC recommended releases document - link below - more accurate than the download pages for recommended releases.

3.  The WLC runs the IOS-XE software.  The SMU are software patches for the IOS-XE on the WLC.  The APSP are software service packs for the APs themselves.  SMUs and APSPs are specific to each version of IOS-XE.

4.  The config guides have upgrade instructions and there are plenty of videos and blogs you can find if you search.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/config-guide/b_wl_17_9_cg/m_upgrade_9800cl.html