MAX STA Report on DNAC for Wireless clients

[Najib Akbari]

I am getting this warning on DNAC for wireless clients here and there:

Reason Description

Max Number of supported clients reached for the AP Radio.

I am using C9800 on 17.9.5

and APs are C9164 and C9124

barely see 5 clients connected on any AP but still get this warning sometimes. is there anywhere to check and tshoot?

here what set on ap profile:

Maximum Client Limit 0

[pengus · Accepted solution]

I tried disabling Load Balance and Band Select in the wlan profile and the problem was fixed. But I don't have a clear answer as to why it was fixed. If your problem persists, you can try it and it may fix your problem too.

[Najib Akbari]

Thank you for letting me know.

I did the same last week as TAC suggested and resolved the issue by just disabling "load balance" which is aggressive-load balance. here is the summary if logic behind it:

aggressive load balance means if the AP passed certain threshold of client window then it sends response code 17 to new client telling Im busy and if client is smart enough will try to associate with another less busy AP and if not then try again and fail again until denial threshold reach then AP will let it associate. some clients does not understand code 17 response so keep trying and failing ......

there are two parameters when enable "load balance" : "window" which can set from 0 to 20 indicating the max number of clients this AP serve until it sends code 17 saying im busy. the other one is "denial" means how many times the AP responds busy then accept if another try comes from same client.

according to TAC and documents better first try to tune those two parameters and see if the issue fixed and if not then disable "load balance". my understanding is it depends on the envirenment, lets say if the client does not support code 17 then it keeps trying and failing ... so maybe disable it for that SSID.

that was the summary of TAC info and my research. here is two document to refer:

https://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/107457-load-balancing-wlc.html

https://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/107457-load-balancing-wlc.html