MBSSID Issue

jmmerritt · ‎07-04-2008

I have several 1130AG LWAPP's running 12.4(13d)JA connected to a contoller running 5.0.148.

2 SSID's are broadcast - usually no problem.

However, I've noticed that several different vendor wireless cards cannot see both SSID's.

Running a wireless capture, I can see that in reply to my probe request, I receive 2 probe responses. The only difference between the two 802.11 frame bodies is that for the SSID that I cannot see there is extended channel switch announcement (ECSA) information.

I'm slight confused as 1.) The SSID's are on the same antenna so shouldn't ECSA be on both beacon reponses? 2.) ECSA profile on 802.11b/g is wmm - wmm is disable both WLAN's.

Scott Fella · ‎07-04-2008

You are right, ECSA should be seen from the same radio if captured at the same time. You have auto RF enabled, have you tried to disable that feature and see if that makes a difference. You also mentioned that certain vendor cards cannot see the ssid. Have you looked at the driver version and device configuration for those cards. Also, what utility are you using, windows zero or a 3rd party... or a mix?

-Scott
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jmmerritt · ‎07-04-2008

I'm not sure changing Auto RF will make much difference. The Power and Channel settings are fine.

We use WZC.

I can solve the issue by upgrading internal users drivers. Specifically Intel 4965AG driver 11.1 to 11.5 - but the release notes don't imply any changes that are related to my problem and I'm reluctant to force this on 300+ people without a solid conclusion.

However I have no control over external guests WIFI drivers. So far its been a 50-50 hit/miss of them seeing the 2nd SSID (our GUEST ssid).

I'm sure its an 11n option but they are def. disabled on the WLC.

Scott Fella · ‎07-04-2008

If your channel changes or power changes ECSA happens. ECSA happens also if 40mhz channel width is enabled, which it isn't in your environment. I don't think this is your issue. From my experience with guest access and users not seeing the ssid, is due to old client drivers. Like you said, you can't control the guest network which makes it difficult.

As far as you Intel 4965AG, that is pretty new. Its guest users that are using drives from 2003 or so.

On the guest ssid, disable WMM, disable Aironet IE, and make sure MFP is disabled or set to optional.

-Scott
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jmmerritt · ‎07-04-2008

Cheers. Guest SSID already has WMM, Aironet IE and MFP disabled.

The only difference between the two SSID's is one WPA and the other is WEP (Guest) :(

Scott Fella · ‎07-04-2008

Oh... I was thinking you were using WebAuth for guest. Well the only thing is to test one of the clients that isn't working if possible and see if updating the drivers will work.... if you can! If you create another ssid for testing and setting it to open no encryption, does this help. You then can eliminate the fact if its WEP or not. WebAuth is the way to go... you create a username and password and change it every day or week. And then you would have no encryption and broadcast the ssid.

-Scott
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jmmerritt · ‎07-04-2008

We're still using WebAuth for the Guest SSID - we also enabled WEP due to DHCP depletion because of Open Auth.

I'll try pushing a test open SSID and see what happens.

Scott Fella · ‎07-04-2008

Sounds good.... let us know how it goes.

-Scott
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jmmerritt · ‎07-04-2008

Pushed out an Open WLAN, Aironet/MFP/WMM disabled.

This means I now have three WLAN's on the same radio. 1) WPA 2) WEP and 3) Open

Did a network scan and was only able to see WLAN 1 (WPA).

Packet capture displays that extended channel switch announcement (ECSA) information is present in the WEP and OPEN probe response, but not in the WPA probe response.

Grrrrr.

Scott Fella · ‎07-04-2008

Try to have one device associated to the new and guest ssid and take a capture.

-Scott
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