topic Re: About client roaming when EWC AP is limited to 20 in Wireless

About client roaming when EWC AP is limited to 20

fakestar2001jp — Mon, 05 Jul 2021 20:23:05 GMT

Access point: catalyst9120 x 40 units
IOS-XE version: 17.3.1.9
Connected device: iPad 8th generation

One of them operates as EWC

The access point in the catalyst 9120 running as an EWC can only connect 20 devices due to the 20 device connection limit.

In the place where the EWC access point is operation, multiple catalyst9120s are also installed, but only 20 devices can be connected.

I think that 20 or more devices may be roamed and connected to other access points, but they are not actually connected.

Do you have any information such as settings to avoid?

Re: About client roaming when EWC AP is limited to 20

Scott Fella — Wed, 02 Jun 2021 16:31:49 GMT

I don't know where you got your information, but here is the FAQ for the EWC:

Q. What are the scale limits for the Embedded Wireless Controller on Catalyst Access Points?

A. The Cisco Catalyst 9105AXI, 9115AX, and 9117AX Series Access Points running the EWC support up to 50 access points and 1000 clients. The Catalyst 9120AX and Catalyst 9130AX Series running the EWC support up to 100 access points and 2000 clients.

Unless you defined max client on the wlan, I don't see how you only have 20 devices max.

Re: About client roaming when EWC AP is limited to 20

fakestar2001jp — Thu, 03 Jun 2021 00:43:08 GMT

Thanks for the reply.

Yes, as you pointed out, the network as a whole has 2000 clients, 100 access points.

However, if more than 25 access points are participating in the EWC network, only up to 20 clients can be connected at the access point where EWC is running.

The following is a description.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/ewc/17-3/rel-notes/ewc-rn-17-3-x.html

Notes for Maximum APs and Clients Supported

The access point that EWC is running on only allows 20 clients to connect.

My understanding is that they will roam to another access point that is recognized in the same location.
However, there is no roaming and the clients are not connected to the wireless.

The SSIDs are all the same.

If I physically leave the access point where I am running EWC, it will automatically connect to another access point.

Re: About client roaming when EWC AP is limited to 20

Scott Fella — Thu, 03 Jun 2021 03:49:25 GMT

Okay, so the easy design for this is to have the EWC ap defined just sit in a closet with the SSID’s disabled. This only affects the ap in which is the EWC controller.

Re: About client roaming when EWC AP is limited to 20

fakestar2001jp — Thu, 03 Jun 2021 08:06:41 GMT

Thank you, Scott Fella.

That's one solution. I will try to verify it.
However, since we are operating the EWC automatically, we need to fix it.

However, when the number of connections to the access point where EWC is running reaches 20, how are the connection requests for the 21st and later devices handled?

I thought it would be rejected and the connection request would go to the same SSID of another access point.
After the 21st access point, there is no connection to any other access point.

Re: About client roaming when EWC AP is limited to 20

Scott Fella — Thu, 03 Jun 2021 09:07:25 GMT

What happens is that any new client will get rejected. The ap will send a reject status code 17, however, if the client doesn’t understand this, the client would ignore this and try to keep associating to that same ap. Remember that the client is in charge of its association and roaming. This is the same if you set the max number of clients in a given ap or if you enable client load balancing. There are other techniques in which the ap will suppress the beacon but again, if the devices chooses that ap because the others are too far or has too many clients already as an example, then this would cause poor user experience as they would notice that they are connecting and dropping or just loosing connection to a service.