WLC 5508 -lot of data send to APs

[Vincent Carrette]

Hello to all,
We have 2 WLC 5508 controllers in active/passive mode and we notice a lot of data is sent by the controller to the AP on the management interface.
For about 300 APs we see 800Mb/s of traffic out of the controller.
Version: 8.5.171.0
AP: 3800, 3700

attached, the 1 hour data for the AP

thank you for your help

[marce1000]

  1) Try to examine wireless client data traffic (too)              2) Get traffic data (volume)  from the controller uplinks to the Intranet such as source and destination(s) included . These topics may provide more insights as to where the traffic is coming from , 

 M.

[Vincent Carrette]

Hi Marce,

The important traffic observed is the flow out of the controller.
The user flow is higher.
Attached :
- A capture of the incoming and outgoing traffic of the controlleur.
- Capture on a remote site where we have 25 AP. The internet speed is higher but we see a high speed on the LAN.
Almost no traffic data to the controller

Vincent

[marce1000]

  - Besides traffic volumes , you need to expand traffic top talkers (sending data) and receiving (also for wireless clients) and also top applications , 

 M.

[Gaurav Kansal]

Dear Vincent,

Did you noticed this heavy traffic randomly or you check this periodically..?
There would be traffic load if you are running hundreds of access points. Please recheck that this traffic is out from management Interface.

GoodLuck..

[Vincent Carrette]

Hello and thank you for your answer,
We check it regularly because we have had bandwidth problems.
The traffic is well out of the management interface.
We have 300 access points. The traffic increases proportionally with the number of connected customers

[Scott Fella]

I can see that because if your design was local mode, then all the ap and user traffic would be hitting that management interface and going out a specific interface.  So the more clients possible more traffic, but specific users/devices can also try to hog up the bandwidth if they are streaming or downloading/uploading large files.  We have seen this when we had a sales meeting with folks from all over the world.  The first day, everyone had their laptops on and was trying to sync emails and basically killed the wireless experience.  

If using FlexConnect as an example, traffic will egress the ap to the adjacent switch and the switch handles the traffic.  Only management traffic (control plane) to and from the aps would be hitting the management interface.

[Vincent Carrette · Accepted solution]

Hello everyone and thank you for your help,
we have found the problem.
It is a "mDNS" problem. The "mDNS global Snooping" function was not activated, which causes a lot of traffic on the network (same SSID).

 Traffic from the controller is back to normal

We found the problem with a packet capture

Vincent