FortiAP
FortiAP devices are thin wireless access points (AP) supporting the latest Wi-Fi technologies (multi-user MIMO 802.11ac Wave 1 and Wave 2, 4x4), as well as 802.11n, 802.11AX , and the demand for plug and play deployment.
syadav
Staff
Staff
Article Id 337615
Description This article describes a known issue that users might encounter while connecting to Wi-Fi 6 (802.11ax) enabled FortiAPs.
Scope FortiAPs with support for Wi-Fi 6/802.11ax (see: FortiAP Wi-Fi 6 Standard and UTP Access Points).
Solution Known Issue #923964 impacts the wireless clients attempting to connect to wireless SSIDs broadcasted from Wi-Fi 6 (802.11AX) enabled FortiAPs.


The problem occurs when a wireless client connects to the SSID and attempts to request an IP address via DHCP. During the DHCP process, the FortiAP transmits the DHCP Offer to the user, but the user fails to acknowledge this packet, therefore it cannot reply with a DHCP Request message; then it times out and finally retries the whole DHCP process.

 

On reassociations, the AP receives a DHCP Request and replies to it with a DHCP Acknowledge but the client cannot process this packet either. This results in the user getting an APIPA address (169.254.x.x) instead of the correct DHCP IP address.


A fix for this issue will be delivered in the upcoming FortiAP firmware v v7.2.6, v7.4.4 and v7.6.1.

 

Check first that all configurations on the switch port are correct and upgrade the FortiAPs to the latest available version.


Workaround:

As a potential workaround, disable BSS coloring first:

  1. Disable partial bss color under VAP:

 

config wireless-controller vap

    edit "vap-name"
        set bss-color-partial disable

end

 

  1. Set the BSS color to static.


    FG # config wireless-controller wtp-profile
    FG (wtp-profile) # edit 431F
    FG (431F) # config radio-2
    FG (radio-2) # set bss-color-mode static
    FG (radio-2) # set bss-color 10

     

As a last resort alternative try disabling 802.11AX on the SSID in the FortiAP profile.

 

To disable 802.11AX, navigate to WiFi & Switch Controller -> Operation Profiles. Select the FortiAP profile then remove 802.11ax in the band configuration.

 

syadav_0-1724960296731.png

 

 

Always engage the Fortinet TAC representative first to ensure matching this behavior.