Experience case of frequent AP disconnection after AC version upgrade at a site

not involving

After the AC is upgraded from the old version (R5207) to the latest version (R5446p09), all APs are frequently disconnected. The disconnection frequency of each AP is about once every ten minutes. Before the version is upgraded, it can be used normally.

First check whether the upgraded version of the AC is compatible with the version of the AP. The version verification is not disabled in the configuration of the AC, and the AP is also upgraded to version 2446p09 simultaneously. There is no problem with the version matching.

The log of the AC records that the reason for the AP going offline is AP was reset due to inconsistent local and reported radio statistics, and the verbose information of the AP shows the reason for going offline: Last reboot reason (AC check): The radio physical status was down, preliminary Judging that the two offline reasons are related to the status of the radio port of the AP, check the configuration of the site again and find that the 5G radio is not used on site, and radio disable is configured on all 5G radios of the AP:

Under normal circumstances, it is difficult to connect the frequent disconnection of the AP with the configuration of radio disable on the radio interface. Let the customer cancel the relevant configuration and observe. The result is still the same, and the AP is still frequently disconnected. It is once every ten minutes, the time is very regular, and the reason for the disconnection is also clearly recorded. Last reboot reason (AC check): The radio physical status was down. It is suspected that the radio frequency of the AP triggered a certain mechanism on the AC. resulting in disconnection.

Log in to the AP remotely to check, and found that the WLAN-Radio1/0/1 interface of the AP has the following configuration:

interface WLAN-Radio1/0/1

shutdown

The customer shuts down the WLAN-Radio1/0/1 interfaces of all APs by delivering the map file, and after the undo shutdown of the interfaces, the APs are online stably.

Later, I learned that this is a protection mechanism added by the new version to prevent the radio port of the AP from going down during normal use, so the old version of the AP can be stably online.

Delete the shutdown configuration under WLAN-Radio1/0/1 of the AP's radio interface, and the AP can go online stably.

If you do not need to use a certain radio port, do not perform shutdown operations on the radio port of the AP. Regardless of whether it is radio 1 or radio 2, as long as the shutdown operation is performed on a radio port on the AP, the AP will restart frequently. AP registration online radio port is closed by default, which radio port needs to be used can be opened with radio enable.