Wireless Access

Hi ,

Am new to WLAN ,have basic doubt rearding VAP(virtual access point). 

Below is my question

1. Suppose AP is divided into 3 VAPs,

2. When these 3 AP's associated with AC(Aruba Controller) ,

    what my thinking is 

    BSSID is same for all with different SSID's.

    BSSID is Mac address of AP so it will be same.

   Please correct me if my understanding is not correct.

Appreciate your quick response.

If I understand your questions correctly:

When you assign multiple Virtual APs to an AP Group or single AP, the following takes place:

1) The AP will advertise an SSID for each VAP

2) Each advertised SSID will have a unique BSSID.   The BSSIDs are not the same as the AP's MAC: they are a derivation of it; each BSSID incrementing in value

Thanks Clembo ,  from your answer what i understood was , BSSID is not exactly the MAC address of AP and MAC address is part of BSSID.

 Some  further explanation; Article ID 386 from Aruba KB.

1) Take the AP Ethernet MAC address and shift the last 20bit to the left by 4 bits. For example, with: 000b86123456 take the last 20bit, which is 23456, and shift to the left to become: 

234560

2) Replace the last 24bit with the shifted value: 000b86234560.

     This becomes the first BSSID of the AP.

• If this AP is an 802.11b/g single radio AP, this is the first BSSID on the b/g band.
•  If this AP is an 802.11a single radio AP, this is the first BSSID on the a band.
• If this AP is a dual radio AP (both enabled), this is the first BSSID on the b/g band.

3) For each virtual AP added to this AP, the last 4bit is increased. Right now our restriction is 7x virtual-AP + 1x base-AP per radio. So the legitimate BSSIDs values for all single radio AP should be within 0 and 7 in the last 4bit.

4) For dual radio AP, 802.11a BSSID ends with 8, 9, a, b, c, d, e, and f.

Below is an example:

AP MAC -         6c:f3:7f:c1:06:21

SSID 1 (2.4) - 6c:f3:7f:90:62:10

SSID 2 (2.4) - 6c:f3:7f:90:62:11

SSID 3 (2.4) - 6c:f3:7f:90:62:12

SSID 1 (5.0) - 6c:f3:7f:90:62:18

SSID 2 (5.0) - 6c:f3:7f:90:62:19

SSID 3 (5.0) - 6c:f3:7f:90:62:1a

Below is an example:

AP MAC -         6c:f3:7f:c1:06:21

SSID 1 (2.4) - 6c:f3:7f:90:62:10

SSID 2 (2.4) - 6c:f3:7f:90:62:11

SSID 3 (2.4) - 6c:f3:7f:90:62:12

SSID 1 (5.0) - 6c:f3:7f:90:62:18

SSID 2 (5.0) - 6c:f3:7f:90:62:19

SSID 3 (5.0) - 6c:f3:7f:90:62:1a

Hi From the above example the BSSID address should be SSID 1- 6c:f3:7f:10:62:10  rather i see 6c:f3:7f:90:62:10  same for all other SSID . May you clarify if my understanding is wrong ?

Thank you once again for timely help