Here's the method to count the BSSID:
1. When you get the AP, you can see the LAN MAC addresses on the AP sticker.
Let's use 00:13:49:12:45:01 as an example.
2. The first BSSID of the 2.4GHz SSID will be 00:13:49:12:45:02 and the first BSSID of the 5GHz SSID will be 00:13:49:12:45:03.
3. The counting of continuous BSSID will apply the following formula:
VAP1 - 0X:13:49:00:12:YZ
VAP2 - 0X+2: YZ :49:00:12 :Y((Z + 1)
VAP3 - 0X+2: YZ :49:00:12 :Y((Z + 2)
4. So, the BSSID of 2.4GHz will be
BSSID1 -> 00:13:49:12:45:02
BSSID2 -> 02:02:49:12:45:03
BSSID3 -> 02:02:49:12:45:04