====== MT7621 arp broadcast ======

Symptoms:
  * all wifi clients has internet access
  * after some time, cannot reach wifi client from another client

Affected routers:
  * Netgear R6220 MediaTek MT7621 ver:1 eco:3

Problem introduced by Kernel: [[https://lkml.org/lkml/2022/5/10/253|[PATCH v2] net: dsa: tag_mtk: add padding for tx packets]]

OpenWrt issue: 
  * [[https://github.com/openwrt/openwrt/issues/11942|ARP/broadcast issues for wireless clients on Mediatek-based routers using OpenWrt as dumb AP in pfSense/OPNsense bridged LAN firewall setups on 22.03.3 release, present since OpenWrt 22.03.0-rc2 #11942]]


[[https://github.com/openwrt/mt76/issues/598|broadcasts delivery problem #598]]

Fixed in:
  * r22186-9307c2753980
  * >= v22.03.4