Hi Luca, Johannes, We see that HE STA in 4addr mode is not able to pass traffic since 4addr NDP frame after successful association is blocked in below commit. There is no AP/VLAN interface created on the 4addr AP side as well. commit 41cbb0f5a29592874355 "mac80211: add support for HE" @@ -929,6 +1020,10 @@ static void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local, if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION)) return; + /* Don't send NDPs when connected HE */ + if (!(sdata->u.mgd.flags & IEEE80211_STA_DISABLE_HE)) + return; + skb = dev_alloc_skb(local->hw.extra_tx_headroom + 30); if (!skb) return; Since ieee80211_send_4addr_nullfunc() is only called for successful association of 4addr STA, shall we allow below case alone for HE ? static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata, struct cfg80211_bss *cbss, struct ieee80211_mgmt *mgmt, size_t len, struct ieee802_11_elems *elems) { .. /* * If we're using 4-addr mode, let the AP know that we're * doing so, so that it can create the STA VLAN on its side */ if (ifmgd->use_4addr) ieee80211_send_4addr_nullfunc(local, sdata); .. Whether this 4addr NDP in HE mode will affect any UL-MIMO from the 4addr STA ? Please comment. Thanks, Sathishkumar