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New Member

Multiple SSIDS and disappearing

We have Cisco 3602i access points for the most part, all of which advertise multiple SSIDs.

Very occasionally we see an SSID completely disappear from view, even though others remain solid (I can't say it's all devices as the majority of people who raise the issue have apple devices, but there are the odd one or two who use Windows laptops).

Also, the RSSI seems to fluctuate wildly.

I should add that we have disabled up to 11mbps data rates on the controller and we're running 7.6.100.0 currently, but plan to upgrade to 7.6.110.0 tonight.

I guess my question is how can an SSID just drop off the client view if others on the same AP are fine? 

How does the AP deal with multiple SSIDs and does it prioritise?

I have to add that I've never had this issue and I'm just using a company standard HP laptop with an Intel chipset.

5 REPLIES

Hello, See my comments: Also,

Hello,

 

See my comments:

 

Also, the RSSI seems to fluctuate wildly.

A: This is often how a device hears the frames. Sometimes in high interference you can epxect this to jump around. I normally like to see if all the devices are doing this or just a select few. Sometimes poor clients jump around more than others. 

I should add that we have disabled up to 11mbps data rates on the controller and we're running 7.6.100.0 currently, but plan to upgrade to 7.6.110.0 tonight.

 
A: I dont think turning off lower rates are bad unless your WiFi cant support the design. Good call get on the latest. 
 
 

I guess my question is how can an SSID just drop off the client view if others on the same AP are fine? 

A: Again, its a client missing frames like beacons. 
 

How does the AP deal with multiple SSIDs and does it prioritise?

 
A: This SSIDs are virtualized. I blogged how this is done:
http://www.my80211.com/home/2011/5/2/wlc-how-cisco-virtualizes-the-base-radio-mac-address-on-the.html
 
 

I have to add that I've never had this issue and I'm just using a company standard HP laptop with an Intel chipset.

A: Again I think if you search you might see this is more around specific devices. I would do a packet capture and see what is going on. Recently had to troubleshoot an Android only to find out it was just bad wifi client. Always sending NULL frames and scanning and not passing traffic 
__________________________________________________________________________________________ "Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin ___________________________________________________________
New Member

Thanks George. Just thought..

Thanks George. Just thought....could load balancing or band select cause an issue with certain clients? I have both of these set on the SSID.

Yes, I would think so. Both

Yes, I would think so. Both have a dynamic play on how devices connect. 

__________________________________________________________________________________________ "Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin ___________________________________________________________
New Member

Ok well I upgraded to 7.6.110

Ok well I upgraded to 7.6.110.0 last week and we're still seeing the WLAN SSID disappear and cut people off. Pretty sure the controller configuration is as safe as I can make it.

Now...today I realised I didn't upgrade the FUS image as well. Would this cause an issue?

I'm upgrading the FUS image across all controller tonight, so if it is causing issues then it should be fixed tonight.

VIP Purple

Yes, upgrade FUS to 1.9.0.0

Yes, upgrade FUS to 1.9.0.0 as that is the recommended version. Keep in mind this will have 30-40 min outage to your wireless.

Also when do you first notice this issue ? SSID dissapearance happen to both 2.4GHz or 5GHz clients or only to specific band ?

 

HTH

Rasika

*** Pls rate all useful responses ***

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