Roaming issue

In one of my client’s office, there’s a decent amount of WAC6503D-S (50+) managed by NXC2500. Recently they report an issue of WiFi roaming.

It happens when staff moved around meeting rooms, start making video calls for a few minutes then WiFi dropped. Sometimes it drops for 4-5 seconds and resumed, but sometimes they have to manually disconnect & connect to that SSID.

The part puzzles me is why the WiFi dropped AFTER the station moved to a new location and having calls for 10+ minutes, which indicated the station should have completed roaming to a stable connection, isn’t it?

I can duplicate it using a ACER laptop with the following WiFi NIC:

Do you have any suggestions?

All Replies

  • Zyxel_Bella
    Zyxel_Bella Posts: 300  Zyxel Employee

    Hi @IT_Patty


    Welcome to Zyxel community!

    Can you help provide the following information for our investigation?

    1.      When the event happens, use admin privilege to run “netsh wlan show wlanreport” on that laptop, the report provides wlan events info of the laptop.


    2.      Collect diagnostic file of NXC after event happens and tell us the timestamp.


    Please send files through private message to me. Thank you.




  • Zyxel_Bella
    Zyxel_Bella Posts: 300  Zyxel Employee

    Hi @IT_Patty


    Files received, thank you. There are two findings from the logs.

    1.      FT: STA Roaming fail. with reason is Invalid PMK-ID

    This should be related to a known issue to us when this NIC works in 802.1x environment. This can be fixed by upgrading its driver to latest version. But this version can only be available from website, don’t just update from WiFi NIC window on laptop.


    2.      STA has blocked by prev-Auth Failed.
    STA Disassociation(2:PREV_AUTH_NOT_VALID) by Hostapd.
    STA has blocked by Hostapd.


    The logs indicate an issue in previous firmware version. Station will be blocked if the group key update happens after fast roaming so sometimes you have to re-connected to SSID to deal with the problem.

    This issue less happens by default because the group key update timer default is 30000 secs, but your config set it to 1800 secs so that’s why you feel it more often.

    We can provide you a date firmware for fixing group key handshake failed case. Would you like to upgrade? We’d appreciate any feedback from you. If you require any further information, feel free to come back to us.

  • Hi Zyxel support,

    Thanks for the information.
    After I upgraded my notebook wireless card driver, I did calls and it works alright!
    If the firmware is released, I’d like upgrade the firmware. Please inform me at once.

  • Zyxel_Bella
    Zyxel_Bella Posts: 300  Zyxel Employee

    Hi @IT_Patty


    We've sent the NXC2500 firmware for fixing group key handshake failed case for you.

    Welcome your active of product experience sharing on Zyxel community.




  • Heinrich
    Heinrich Posts: 1
    I face exactly the same issue:
    [STA Disassociation(2:PREV_AUTH_NOT_VALID) by Hostapd.] and service interruption.

    We are running V6.10(AAIG.2) / V1.06 / 2021-01-21 on the NXC2500.
    Please provide the firmware upgrade also to me.