ZD1100 processor at 100% with 40 tablet loading (w00t?)

[kristijan_fabin]

Dears,

I had one experience with ZD1100 in one school where we deployed around 10 AP's 7372's mostly. One AP is in the "Samsung classroom" where they booted up 40 tablets at once connecting to the AP.
WPA is on. After successful connection they logged in on local Samsung server.

At the same time while they were booting, ZD1100 processor was on 100% for 10-15 minutes. I wasn't even able to load a single page in administration. Each page was loading for like 10+ seconds or even 30 seconds. It was crazy.
After that it was fine and ocassionaly I see spikes at 100% which are lasting for a few seconds but sometime even a 2-3 minutes.

Firmware is 9.8.

My questions:
1. Is that normal? Others have similar/same experience?
2. Is that caused because of WPA? or because 40 clients loaded at once?
3. If that because 40 clients loaded at once I wonder what will happen if 1000 clients loads at once? Limit is 1250 simultaneous. I havent had chance to have more than 600 devices on ZD1100 but this experience is new to me

Picture attached is not the real one when I had that problem, more like a visual add-on to this post :)

[koen_verbeeck]

Hey Kristijan.

What WPA version are you using?
WPA-TKIP or WPA2 AES CCMP?
What is the exact version of the firmware you are using?

Greetings

[kristijan_fabin]

Hi Koen

Exast firmware version is 9.8.0.0 build 373
Auth option is 802.1x EAP, Encryption is WPA2 (TKIP+AES)

[monnat_systems]

Hello Kristijan Fabina,

1. Is that normal? well i have heard however for different reasons due to heavy client and traffic load via tunnel.

2. Is that caused because of WPA? or because 40 clients loaded at once? well as per my experience not really because of WPA but 40 in one shot client load can trigger temporal spike. i think we can try open WLAN to test the WPA theory.

3. If that because 40 clients loaded at once I wonder what will happen if 1000 clients loads at once? Limit is 1250 simultaneous. I havent had chance to have more than 600 devices on ZD1100 but this experience is new to me

Well in real life scenario you will never see 1000 clients connecting in one shot then ZD1100 will certainly run into trouble.

Picture attached is not the real one when I had that problem, more like a visual add-on to this post 🙂

Quick checks to try:

Try with a OPEN WLAN to see if processor shoots up to 100 % or not?
Do not use real time monitoring. It does not suit ZD1100 at all.
See if you are using tunnel traffic for this WLAN to ZD, if yes, then try putting it off and test?

hope this helps.

[michael_brado]

Hello Kristijan,

Comments above are relevant. High number of total clients can increase CPU
resources, as will having tunneled WLANs. 40 iPad clients all connecting on
one AP may impact the AP slightly, but above that is 802.1x RADIUS exchange
where the ZoneDirector is the NAS to your AAA server. A test with Open Auth
might likely show faster total client connection speed. I don't think your WebUI
should have slowed down unless there was network congestion from your PC
to the ZD. Do you have GigE switch port connecting to your ZoneDirector?

To help streamline your present WLAN, please use WPA2 Method (not WEP or
WPA-Mixed) and Algorithm of AES (not TKIP or Auto), a WPA2/AES combination.
Please evaluate with 9.8.1.0.101 too, over 9.8 earlier release of ZD firmware.
I hope this is helpful.