https://www.gargoyle-router.com/phpbb/viewtopic.php?f=5&t=9267&hilit=Bssid

In a situation were the AP and more than one bridge/repeaters have the same SSID we need to force the bridge/repeater to lock on to the AP. To do this we use the MAC address of the WLAN AP.

When selecting the SSID to join we need to manually edit /etc/config/wireless to ensuring it uses the correct AP.

first you'll need to know the BSSID of the one you want to connect to. if you're on 2.4ghz, at the command line type “iw wlan0 scan”

SSH into your client router with putty

<shell> iw wlan0 scan </shell>

Find the MAC address. In this case “BSS aa:aa:aa:aa:aa:aa”

<shell> BSS aa:aa:aa:aa:aa:aa(on wlan0) – associated

      TSF: 164972434397 usec (1d, 21:49:32)
      freq: 2462
      beacon interval: 100 TUs
      capability: ESS (0x0421)
      signal: -32.00 dBm
      last seen: 0 ms ago
      Information elements from Probe Response frame:
      SSID: Gargoyle
      HT capabilities:
              Capabilities: 0x11ed
                      RX LDPC
                      HT20
                      SM Power Save disabled
                      RX HT20 SGI
                      RX HT40 SGI
                      TX STBC
                      RX STBC 1-stream
                      Max AMSDU length: 3839 bytes
                      DSSS/CCK HT40
              Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
              Minimum RX AMPDU time spacing: 8 usec (0x06)
              HT TX/RX MCS rate indexes supported: 0-23
      HT operation:
               * primary channel: 11
               * secondary channel offset: no secondary
               * STA channel width: 20 MHz

</shell>

In this case we install nano to edit “/etc/config/wireless”. We could use other methods like vi or WinSCP.

<shell> opkg update opkg install nano nano /etc/config/wireless </shell>

Add the line “option bssid 'aa:aa:aa:aa:aa:aa'”

<shell> config wifi-device 'radio0'

      option type 'mac80211'
      option channel '11'
      option hwmode '11g'
      option path 'platform/qca955x_wmac'
      option htmode 'HT20'

config wifi-iface 'cfg2'

      option device 'radio0'
      option network 'wwan'
      option mode 'sta'
      option client_bridge '1'
      option ssid 'Gargoyle'
      option bssid 'aa:aa:aa:aa:aa:aa'
      option encryption 'none'

config wifi-iface 'cfg3'

      option device 'radio0'
      option network 'lan'
      option mode 'ap'
      option ssid 'Gargoyle'
      option encryption 'none'

</shell>