Issue with maintaining an eWLC active when another is already active

[Soxi]

Hello everyone, I am currently working on a project to implement 10 Cisco AP C9105AXI-E in my company's building.

I am quite a beginner in the domain of Networks and Telecommunications and I encounter an issue with my APs.

At the moment, we already have a bunch of Cisco AP Aironet 1815 that are working correctly (I didn't install them).
Recently, we ordered the C9105 to have a better wireless cover in the building. They can provide WiFi-6, where our 1815 can't so we decided to separate them.

Now regarding my part

I configured the new APs (the 9105) with one of them as a WLC (eWLC if I understood well, with a GUI on the web as a 9800 WLC series it looks like) on an isolated network, composed of the WLC, my laptop and as much as APs that i want (I use only 1 to 2 APs with the WLC to have a stadby WLC and a clear AP), all that tied to a little switch.

Now I have the following issue: Once I connect this little switch to the subnet of the 1815 APs (it is a VLAN in our company's network), my WLC instantly drops his role of WLC off and becomes a regular AP just like the others.

The issue is that the other have the 9105 WLC as their primary, but since he is "no longer here", they just tend to ask desperatly to the 1815 WLC to join it, even if they can't.

Here is where I need your help, any suggestions about how I could succeed to make my 9105 WLC stay a WLC, so each model of AP stay joined to its respective WLC ?

You can find attached a screenshot of the logs of the WLC 10 secs after linking my isolated network to our company's network when he drops his role by deleting its files, after what it gets back its name and role of regular AP.

Thanks a lot in advance for your help.

[marce1000 · Accepted solution]

                            >...so each model of AP stay joined to its respective WLC ?
 - Basically you can't , you need to streamline your controller setup and limit and or migrate  to 'one'  and or remove the mobility express based solutions (on the 1815's) , because AP's can for instance do capwap broadcast to find a controller. 

 M.

[Soxi]

Thanks for you answer Marce.

So if I get it right, the infrastructure I seek is not possible to build because of the unavoidable discovery and join processes that are directly the purpose of the CAPWAP protocol.

And even if I would like to do something that is as close as what I want, I would either have to :

- Get rid of the 1815

- Place the two models on a different VLAN (or subnet) so they wont interfere anymore

[marce1000]

                        >...- Place the two models on a different VLAN (or subnet) so they wont interfere anymore
 - Yes , long term better plan is to go for single controller solution (streamlining the wireless environment and management) , this thread shows how to convert the 1815 to capwap too (if they would be kept) : https://community.cisco.com/t5/wireless/air-ap1562i-e-k9-from-mobility-express-ap-to-capwap-ap/td-p/4765829

 M.

[Soxi]

Ok, thanks a lot for your reactivity and for your help !