Is it possible to upgrade Cisco 9800 with ISSU along with SMU?

[jegan_rajappa]

Hi All, I am fan of Cisco 9800 as it allows to take advantage of ISSU, when I test 17.3.5a Image in pair of 9800-CL appliances with ISSU, all works well except 2702 IOS APs, after upgrade 2702 APs couldn't join the controller.

Upon investigation, It seems my controllers were hitting CSCwb13784 bug, the good news is that Cisco have released SMU for the same which allows 2702 to join the controller, however this bug is not allowing me to take advantage of ISSU as it creates longer down time, I cannot say Zero down time anymore because of this bug.

Is anyone experiencing the same? Is there any way to install SMU along with ISSU workflow?

[Prince.O]

Hello,

SMUs can be applied to the controller without requiring a reload of the box so this can be applied without downtime and do not require ISSU option

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/config-guide/b_wl_16_10_cg/software-maintenance-upgrade.html

[jegan_rajappa]

My concern is different @Prince.O , ISSU allows to perform software maintenance minimizing downtime or zero downtime if it is carefully designed, the problem is about the bug, because if the defect in the bug, Several APs according to bug (Cisco 2702 APs in my case)  cannot join the controller after upgrading the controller to 17.3.5a with ISSU, post ISSU process, I can add the SMU which allows those APs to join the controller, however that comes with longer downtime, I am unable to take advantage (Values) of ISSU because of this bug.