# RTL8735B (AmebaPro2) WiFi STA drops incoming multicast after WLAN update — worked before

**URL:** <https://forum.amebaiot.com/t/rtl8735b-amebapro2-wifi-sta-drops-incoming-multicast-after-wlan-update-worked-before/5016>\
**Category:** WiFi\
**Tags:** rtl8735b, evb-amb82\
**Created:** [August 20, 2026, 1:30pm UTC](https://forum.amebaiot.com/t/rtl8735b-amebapro2-wifi-sta-drops-incoming-multicast-after-wlan-update-worked-before/5016 "2026-08-20T13:30:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![yugandhar](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/yugandhar/32/2836_2.png) [@yugandhar](https://forum.amebaiot.com/u/yugandhar)\
**Post date:** [August 20, 2026, 1:30pm UTC](https://forum.amebaiot.com/t/rtl8735b-amebapro2-wifi-sta-drops-incoming-multicast-after-wlan-update-worked-before/5016/1 "2026-08-20T13:30:32Z")

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Hi,

Our app runs a standard UDP multicast listener (ONVIF WS-Discovery, 239.255.255.250:3702). Over WiFi STA, multicast packets never reach it — no matter what, even with a confirmed successful `IP_ADD_MEMBERSHIP` join. Send the exact same packet as **unicast** to the device’s own IP/port instead, and it responds instantly and correctly.

That isolates it cleanly: the socket, the join, and the app logic are all fine — this is the WiFi driver not delivering multicast-addressed frames up to the stack anymore.

Is there any known change in STA-mode multicast RX filtering in a recent WLAN component release?Or any driver-level way to force multicast acceptance in STA mode?

Thank you,

Yugandhar

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**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/ameba/original/2X/7/7009caf971627f868f3de3d34312aff2d14c61e3.png) [@system](https://forum.amebaiot.com/u/system)\
**Post date:** [August 20, 2026, 1:30pm UTC](https://forum.amebaiot.com/t/rtl8735b-amebapro2-wifi-sta-drops-incoming-multicast-after-wlan-update-worked-before/5016/2 "2026-08-20T13:30:36Z")

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👋 Thanks for your post!

For documentation, SDK resources, FAQs, and community guidelines, please visit: [here](https://forum.amebaiot.com/t/forum-community-guidelines-and-resources/4969)

Happy building with Ameba!

* * *

👋 感谢您的发帖！

如需查阅官方文档、SDK 资源、常见问题（FAQ）及社区使用指南，请参考: [這裏](https://forum.amebaiot.com/t/forum-community-guidelines-and-resources/4969)

祝您使用 Ameba 开发愉快！

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**Author:** ![KevinKL](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kevinkl/32/2632_2.png) [@KevinKL](https://forum.amebaiot.com/u/KevinKL)\
**Post date:** [August 26, 2026, 8:51am UTC](https://forum.amebaiot.com/t/rtl8735b-amebapro2-wifi-sta-drops-incoming-multicast-after-wlan-update-worked-before/5016/3 "2026-08-26T08:51:42Z")

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Hi @yugandhar ,

Could you provide an example code for us to replicate your issue?

Thank you.