Too many SSIDs

[Josh Morris]

I have recently started at a new company. We have 12-14 SSIDs on each controller. I have noticed that wireless performance can be pretty poor at times. As I understand it, the controller will spend a set amount of time servicing each SSID. Therefore, the more SSIDs you have, the longer each has to wait to get serviced.

It sounds like certain apps or vendors said "We need our own SSID, period." And it was done.

Now there are:

(2) WPA/WPA2 + 802.1x

(2) None (extenral reidrection)

(2) Static WEP

(3) WPA/WPA PSK

(1) WPA PSK

(1) WPA2 PSK

(1) Mac filter/web-auth

Anyone have any recommendations on an approach that will help me to consolidate these to get closer to 6 SSIDs?

[George Stefanick · Accepted solution]

Josh,

I actually did study's on this very subject. I found by taking a single AP and enabling 16 SSIDs it uses from 40-60% channel utilization just for management frames. This is a observation on your part. If you have a analyzer do a capture and see for yourself.

What you need to do is partner with the application folks and truly understand there need for their own SSID.

Standardize on a security standard

I work for a very large healtcare system and we have standards and they must be met inorder to connect.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[Scott Fella]

George is right... here is what I tell my clients.... If I connect to any of these SSID's, is there any separation between the subnets you place traffic on? Look at it this way.... What devices need access to what resources and you can probably consolidate the ssid pretty quick.

Sent from Cisco Technical Support iPad App

[Josh Morris]

Thanks guys. I am also in healthcare. Many of these were created long ago and I'm afraid someone yelled loud enough until they got their own SSID. From what I can tell, there is no additional security/routing policy for many of these networks. Therefore, I think their perceived benefit from having their own SSID is null based on the amount of overhead. And George, thanks for sharing your findings. I have not performed the analysis but I am certain we are spening way too many cycles on management.

[George Stefanick]

Josh,

I have 10,000 wireless devices. I call BS. You are right some vendor / dept yelled loud enough .. I feel for you.. It will be a up hill battle.

I would do this . Create a standard that will get most devices to conform to. Some older medical devices wont be able to do AES. So you may be stuck with a WPA/TKIP security.

Good luck .. hit me up on my blog my80211.com if you have specific questions. Ill see what I can do to help .. We likely run the same equipment and apps and have good relationships with some of the vendors.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[Josh Morris]

Also George,

I'm thinking you did something like this in your analysis...

SPAN a WLC port to a sniffer, capture all traffic, then filter fo rmanagement/ap-manager interfaces?

Or am I way off?

[George Stefanick]

No, you want to do a wireless capture. Have you worked with a wireless L2 analyzer ?

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[George Stefanick]

Look at the utilization -- only managment frames ..

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."