I recently reimaged a 9115 AP to 17.12.3, and suddenly the characters on the console became unreadable after the reboot. While other APs on 17.9X were working when connecting to the console, it was later found that Cisco has released a BUG ID CSCwe88390 for this behavior.

Starting from 17.12, if customers perform a factory reset on WiFi 6 APs, the console baud rate will be set to 115200 bps.

Why Cisco has introduced this change, setting the baudrate to 11500 can reduce the overall AP boot up time.

You can set the baud rate on PuTTY to 115200, but if you have APs on other versions, it will be difficult.

Cisco has provided an AP CLI to change the console baud rate. Customers can use “ssh” to log in to the AP console:

configure boot baudrate
115200 baudrate 115200
9600 baudrate 9600