What is the consequence of re-using BSSID values?

[hostapd.conf](https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf) : # hostapd will generate BSSID mask based on the BSSIDs that are # configured. hostapd will verify that dev_addr & MASK == dev_addr. If this is # not the case, the MAC address of the radio must be changed before starting # hostapd (ifconfig wlan0 hw ether ). If a BSSID is configured for # every secondary BSS, this limitation is not applied at hostapd and other # masks may be used if the driver supports them (e.g., swap the locally # administered bit) # # BSSIDs are assigned in order to each BSS, unless an explicit BSSID is # specified using the 'bssid' parameter. # If an explicit BSSID is specified, it must be chosen such that it: # - results in a valid MASK that covers it and the dev_addr # - is not the same as the MAC address of the radio # - is not the same as any other explicitly specified BSSID The last point is violated by hostap generated by LEDE 17.01.2 :(. The multiple interfaces were created using the LUCI web interface. I don't believe this changed since OpenWrt 15.05 either. interface=wlan0 ctrl_interface=/var/run/hostapd disassoc_low_ack=1 preamble=1 wmm_enabled=1 ignore_broadcast_ssid=0 uapsd_advertisement_enabled=1 wpa_passphrase=hunter2 auth_algs=1 wpa=2 wpa_pairwise=CCMP ssid=VOYAGER2091-90-jenkins wpa_key_mgmt=WPA-PSK okc=0 disable_pmksa_caching=1 bssid=74:44:01:86:42:d4 bss=wlan0-1 ctrl_interface=/var/run/hostapd disassoc_low_ack=1 preamble=1 wmm_enabled=1 ignore_broadcast_ssid=0 uapsd_advertisement_enabled=1 wpa_passphrase=hunter2 auth_algs=1 wpa=2 wpa_pairwise=CCMP ssid=VOYAGER2091-alan wpa_key_mgmt=WPA-PSK okc=0 disable_pmksa_caching=1 bssid=76:44:01:86:42:d4 Why does hostapd say it requires distinct BSSIDs? What are the possible results of violating this? In previous versions, I've had problems even creating multiple wifi networks like this. After switching to this LEDE release, it seems able to create the networks OK. However, moving away from the access point to room B, often one network shows up but not the other. (Client is Fedora 26 with an Intel wireless card). But this is within usable range, and if I had already connected to one of the networks, I think it is always able to remain connected when moving to room B. So I'm slightly suspicious about this business with BSSIDs.