Fire OS 8 loses broadcast/multicast reception after WPA2 Group Key (GTK) rekey

Fire Devices & Appstore Q&A
1

Hello,

I would like to report what appears to be a Wi‑Fi interoperability issue affecting a Fire HD tablet running Fire OS 8.

Device

  • Fire HD 10 (Fire OS 8) 2023 model

Network Environment

  • Linux AP using hostapd
  • Intel AX201 Wi‑Fi adapter (iwlwifi driver)
  • WPA2-PSK (RSN)
  • CCMP/AES only
  • IPv4 UDP broadcast discovery protocol running on the tablet

Problem Description

The tablet receives UDP broadcast packets correctly after connecting to Wi‑Fi.

However, immediately after a WPA Group Temporal Key (GTK) rekey operation, broadcast reception stops.

Unicast traffic continues to work normally.

The tablet remains associated to the AP and existing unicast communications continue functioning.

Only broadcast/multicast reception appears to be affected.

Evidence

On the AP, hostapd logs:

WPA: group key handshake completed (RSN)

Immediately after this event:

  • UDP broadcast packets are no longer delivered to applications on the tablet.
  • Existing TCP and UDP unicast traffic continues working.
  • Wi‑Fi remains connected.
  • Reconnecting Wi‑Fi restores broadcast reception, until the next rekey.

Reproduction

  1. Connect Fire HD 10 to WPA2-PSK Wi‑Fi network.
  2. Verify UDP broadcasts are received.
  3. Configure short GTK rekey interval:

wpa_group_rekey=60

  1. Wait for GTK rekey event.
  2. Observe:
    • hostapd reports successful group key handshake completion
    • broadcast reception on Fire OS stops immediately afterward

Additional Testing Performed

Tested with:

  • WPA/TKIP
  • WPA2/CCMP

The issue occurs with both configurations.

Switching from mixed WPA/WPA2 to WPA2-only does not resolve the issue.

Important Observation

Enabling hostapd:

multicast_to_unicast=1

or

wpa_group_rekey=0

completely avoids the problem.

With multicast-to-unicast conversion enabled, the tablet continues working correctly even across repeated GTK rekey events.

This suggests:

  • Pairwise-key (PTK) unicast traffic remains functional.
  • The issue appears specific to traffic protected using the group key (GTK).

Comparison with Previous Device

A Fire HD 10 (2021) running Fire OS 7 does not exhibit this behavior under the same conditions.

The issue has only been observed on the Fire OS 8 device.

Request

Could this report be forwarded to the Fire OS networking / Wi‑Fi engineering team for investigation?

The behavior appears reproducible and may indicate a problem in GTK rekey handling or multicast/broadcast reception after a successful WPA group key update.

I can provide additional hostapd logs, packet captures, and configuration details if needed.

Thank you.

3

Hi,

Thanks for posting. We have messaged the appropriate team for further investigation and will let you know once we receive an update.

4

Hi,

Thank you for your patience with this issue. Could you share the DSN (Device Serial Number) and any relevant logs so we can investigate further?

5

Hi, here is the DSN, as reported by ADB:
GN434K023346010N
I’ve also tested with a different tablet, same model, with the same result.

About the logs: it would be great if you can specify what logs in particular are needed. Here are, however, the logs from the WiFi AP (hostapd/ Ubuntu 26.04), and the year 2023/2021 model tablets. The timestamp of the logs is roughly synchronized. The point to notice is the absence of logging on the newer tablet when the GTK update (group key handshake) happens.

AP. hostapd log after service restart: (Actual AP name redacted for privacy reasons)
$ sudo journalctl -f -u hostapd
10月 13 10:18:55 WIFI-AP-SVR hostapd[3809]: wlan0: AP-ENABLED
10月 13 10:18:55 WIFI-AP-SVR systemd[1]: Started hostapd.service - Access point and authentication server for Wi-Fi and Ethernet.
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 86:6c:fa:fc:3b:3f IEEE 802.11: authenticated
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 48:b4:23:99:c7:69 IEEE 802.11: authenticated
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 86:6c:fa:fc:3b:3f IEEE 802.11: associated (aid 1)
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 48:b4:23:99:c7:69 IEEE 802.11: associated (aid 2)
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 48:b4:23:99:c7:69 RADIUS: starting accounting session DB0F0C3FD21BF04F
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 48:b4:23:99:c7:69 WPA: pairwise key handshake completed (RSN)
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 86:6c:fa:fc:3b:3f RADIUS: starting accounting session 433E03547D2A2D95
10月 13 10:18:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 86:6c:fa:fc:3b:3f WPA: pairwise key handshake completed (RSN)
10月 13 10:19:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 86:6c:fa:fc:3b:3f WPA: group key handshake completed (RSN)
10月 13 10:19:55 WIFI-AP-SVR hostapd[3819]: wlan0: STA 48:b4:23:99:c7:69 WPA: group key handshake completed (RSN)

Tablet log. Using this:

adb logcat | grep -E "wpa_supplicant|GTK|Group rekey|STATE-CHANGE|set_key"

2021 Model: Note “Group rekeying completed” @1010:19:55, matching AP’s.

10-13 10:18:49.140 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=8 BSSID=c93b5946dc4a239fd
10-13 10:18:49.146 15818 15818 I wpa_supplicant: wlan0: WPA: Group rekeying completed with c93b5946dc4a239fd [GTK=CCMP]
10-13 10:18:49.146 15818 15818 I wpa_supplicant: wpa-supplicant freq_2437=1, rssi_5_bar=1 ,rssi=69
10-13 10:18:49.146 15818 15818 I wpa_supplicant: eapol-tx-status-check: reset counter since WPA_COMPLETED is set
10-13 10:18:49.146 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=9 BSSID=c93b5946dc4a239fd
10-13 10:18:49.151 15818 15818 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd MACADDR
10-13 10:18:55.521 15818 15818 I wpa_supplicant: nl80211: Drv Event 103 (NL80211_CMD_VENDOR) received for wlan0
10-13 10:18:55.575 15818 15818 I wpa_supplicant: nl80211: Drv Event 47 (NL80211_CMD_ROAM) received for wlan0
10-13 10:18:55.575 15818 15818 I wpa_supplicant: nl80211: Roam event
10-13 10:18:55.576 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=6 BSSID=c93b5946dc4a239fd
10-13 10:18:55.577 15818 15818 I wpa_supplicant: wlan0: Associated with c93b5946dc4a239fd
10-13 10:18:55.577 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
10-13 10:18:55.595 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=7 BSSID=c93b5946dc4a239fd
10-13 10:18:55.596 15818 15818 I wpa_supplicant: wlan0: WPA: RX message 1 of 4-Way Handshake from c93b5946dc4a239fd (ver=2)
10-13 10:18:55.598 15818 15818 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 2/4
10-13 10:18:55.607 15818 15818 I wpa_supplicant: wlan0: WPA: RX message 3 of 4-Way Handshake from c93b5946dc4a239fd (ver=2)
10-13 10:18:55.607 15818 15818 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 4/4
10-13 10:18:55.609 15818 15818 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd M3_NO_RECEPTION_PARAMS
10-13 10:18:55.609 15818 15818 I wpa_supplicant: get_rssi_statistics
10-13 10:18:55.609 15818 15818 I wpa_supplicant: nl80211 test mode: ifindex=95
10-13 10:18:55.609 15818 15818 I wpa_supplicant: rssi info : auth rcpi = 159 , auth retry =0, assoc rcpi=159, assoc retry =0, eapol rcpi =154, eapol retry =0 
10-13 10:18:55.610 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=8 BSSID=c93b5946dc4a239fd
10-13 10:18:55.614 15818 15818 I wpa_supplicant: wlan0: WPA: Key negotiation completed with c93b5946dc4a239fd [PTK=CCMP GTK=CCMP]
10-13 10:18:55.614 15818 15818 I wpa_supplicant: wpa-supplicant freq_2437=1, rssi_5_bar=1 ,rssi=69
10-13 10:18:55.614 15818 15818 I wpa_supplicant: eapol-tx-status-check: reset counter since WPA_COMPLETED is set
10-13 10:18:55.615 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-CONNECTED - Connection to c93b5946dc4a239fd completed [id=0 id_str=%7B%22configKey%22%3A%22%5C%223371511b76b0ab01%5C%22WPA_PSK%22%2C%22creatorUid%22%3A%221000%22%7D] RSSI: -31
10-13 10:18:55.615 15818 15818 I wpa_supplicant: wpa-supplicant AP_BSSID=a46bb6
10-13 10:18:55.615 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=9 BSSID=c93b5946dc4a239fd
10-13 10:18:55.618 15818 15818 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd MACADDR

10-13 10:19:55.519 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=8 BSSID=c93b5946dc4a239fd
10-13 10:19:55.522 15818 15818 I wpa_supplicant: wlan0: WPA: Group rekeying completed with c93b5946dc4a239fd [GTK=CCMP]
10-13 10:19:55.523 15818 15818 I wpa_supplicant: wpa-supplicant freq_2437=1, rssi_5_bar=1 ,rssi=69
10-13 10:19:55.523 15818 15818 I wpa_supplicant: eapol-tx-status-check: reset counter since WPA_COMPLETED is set
10-13 10:19:55.523 15818 15818 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=9 BSSID=c93b5946dc4a239fd
10-13 10:19:55.524 15818 15818 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd MACADDR

2023 Model: No log for Group rekeying.

10-13 10:18:55.338 21072 21072 I wpa_supplicant: nl80211: Drv Event 103 (NL80211_CMD_VENDOR) received for wlan0
10-13 10:18:55.382 21072 21072 I wpa_supplicant: nl80211: Drv Event 47 (NL80211_CMD_ROAM) received for wlan0
10-13 10:18:55.382 21072 21072 I wpa_supplicant: nl80211: Roam event
10-13 10:18:55.384 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=6 BSSID=c93b5946dc4a239fd
10-13 10:18:55.389 21072 21072 I wpa_supplicant: wlan0: Associated with c93b5946dc4a239fd
10-13 10:18:55.395 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
10-13 10:18:55.410 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=7 BSSID=c93b5946dc4a239fd
10-13 10:18:55.415 21072 21072 I wpa_supplicant: wlan0: WPA: RX message 1 of 4-Way Handshake from c93b5946dc4a239fd (ver=2)
10-13 10:18:55.416 21072 21072 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 2/4
10-13 10:18:55.428 21072 21072 I wpa_supplicant: wlan0: WPA: RX message 3 of 4-Way Handshake from c93b5946dc4a239fd (ver=2)
10-13 10:18:55.429 21072 21072 I wpa_supplicant: wlan0: WPA: Sending EAPOL-Key 4/4
10-13 10:18:55.433 21072 21072 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd M3_NO_RECEPTION_PARAMS
10-13 10:18:55.433 21072 21072 I wpa_supplicant: get_rssi_statistics
10-13 10:18:55.435 21072 21072 I wpa_supplicant: testmode_rssi_statistics_handler
10-13 10:18:55.435 21072 21072 I wpa_supplicant: rssi info : auth rcpi = 143 , auth retry =0, assoc rcpi=168, assoc retry =0, eapol rcpi =149, eapol retry =0 
10-13 10:18:55.436 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=8 BSSID=c93b5946dc4a239fd
10-13 10:18:55.446 21072 21072 I wpa_supplicant: wlan0: WPA: Key negotiation completed with c93b5946dc4a239fd [PTK=CCMP GTK=CCMP]
10-13 10:18:55.446 21072 21072 I wpa_supplicant: eapol-tx-status-check: reset counter since WPA_COMPLETED is set
10-13 10:18:55.447 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-CONNECTED - Connection to c93b5946dc4a239fd completed [id=0 id_str=%7B%22configKey%22%3A%22%5C%223371511b76b0ab01%5C%22WPA_PSK%22%2C%22creatorUid%22%3A%221000%22%7D] RSSI: -36
10-13 10:18:55.455 21072 21072 I wpa_supplicant: wlan0: CTRL-EVENT-STATE-CHANGE id=0 state=9 BSSID=c93b5946dc4a239fd
10-13 10:18:55.459 21072 21072 I wpa_supplicant: wpa_driver_nl80211_driver_cmd: wlan0 recv cmd MACADDR

Please let me know if any other info is needed.

Thanks.

6

Thanks for providing further information. We have messaged the appropriate team for further investigation and will let you know once we receive an update.