APs beaconing a "Hidden" SSID with SSID Wildcard in the capture

[EricHouser]

I am curious as to what I am seeing while monitoring my WLAN and seeing this oddity.  I have never seen this before on any other WLAN except Meraki.  This appears on my MR36 network, and a customer's MR44 network.  If we have an SSID of say, "Business" and "Guest", and looking at the various BSSIDs for both the 5 gHz and 2.4 gHz channels, they are seen fine while using a Netally Aircheck G2 device, but we also start to see a [HIDDEN] network as well using a OUI of a6:18:88 in the frames captured, and the remainder matches the APs themselves so we know it is the Meraki devices doing this.  They appear beaconing as WEP and only using 802.11b and g and while reviewing the packet capture done at the AP level, the SSID is "SSID=Wildcard".  I am looking for an explanation as to what this is being used for.

[Riley · Accepted solution]

I wonder if this behavior is related to some of the mesh capabilities of Meraki access points.  I know that their mesh networks are supposed to be "self-healing" and I am pretty sure there are mesh probes.

https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Wireless_Mesh_Networking

From the doc:

What are mesh probes?

Each Meraki AP sends out link probe packets (known as mesh probes) at different bit rates and varying sizes. Because these packets are sent as broadcast frames, no ACK frames are needed from receiving stations. Four different types of probes at different data rates are sent in a batch of 15 seconds on both (2.4 /5 GHz) bands. All APs listen to the mesh probes and depending on the number of mesh probes correctly received, come up with a link quality metric as shown in dashboard.

[EricHouser]

Yep, you are correct!  Disabled that, and the odd SSIDs disappeared.  Thanks for that!!