C9800-flexconnect

[ridleywoole]

Hello,

I am new to C9800 and Cisco wireless. I've got it working, works OK. But I want to replicate typical setup of Omada or Ubiquity i.e if controller goes down all continue to work as expected. Based on what I have read Flex-connect is the way to go 🙂

When I try to add basic network and switch to FlexConnect, C9800 says not recommended setup. Why is that , flex connect seem more logical to me ?

Is it possible to have external DHCP server(that will be central DHCP, coming from AD), Flex connect and if controller goes down, all to continue working as with the other brands ?

Can you please point me some good tutorial to convert from Local setup to Flex - My setup is simple - 2 APs, 1 single Vlan ? 🙂

Thank you 🙂

P.S Not sure why c9800 is so complicated, Ubiquity and Omada are so simpler. The idea that I think is that I try to use enterprise gear in a very small setup and this where problems come up. But even in large enterprise, time of large central HQ and many tunnels to it passed, so c9800 "central switching" seems so out of time and the billion options c9800 has, not sure even if it large setups they will be used 🙂

[Mark Elsen]

   >...When I try to add basic network and switch to FlexConnect, C9800 says not recommended setup. Why is that , flex connect seem more logical to me ?
      - Flexconnect with local switching is recommended  if the APs are on remote branches still  being able to serve clients when the controller becomes unreachable (e.g.)

  >...Is it possible to have external DHCP server(that will be central DHCP, coming from AD), Flex connect and if controller goes down, all to continue working as with the other brands ?
     - Yes but remember that the DHCP and AD services  then must remain reachable too  in all cases or else use local authentication and DHCP schemes

       >....Can you please point me some good tutorial to convert from Local setup to Flex - My setup is simple - 2 APs, 1 single Vlan ?
                               https://rowelldionicio.com/configuring-c9800-cl-flexconnect/

  Note that when configuring the controller and if you are evaluating a final setup ready for production
  then issue the CLI command show tech wireless and feed the output from that into Wireless Config Analyzer
                     Checkout all advisories given !! + This is so good

 M.

[Rich R]

Marce has already answered your question @ridleywoole but I just wanted to add some points.
Not sure why you thought Flexconnect was not recommended?  As Marce said it is absolutely required in many scenarios and is entirely dependant on your design requirements.  Simply changing an AP to flexconnect doesn't make much difference in and of itself (some association and other functions get devolved from WLC to AP).  What really makes the difference is configuring a WLAN for local authentication and switching - that's what allows the WLAN to continue functioning independent of the WLC.  Of course, as Marce said, that AP must still be able to reach the AAA server(s) directly or if you're simply using PSK then not an issue.   There are some features which behave slightly differently for local auth and local switching.  The feature matrix shows some of those differences: https://www.cisco.com/c/en/us/td/docs/wireless/access_point/feature-matrix/ap-feature-matrix.html#_Toc118737963 with more detail in the config guides which list specific restrictions for each feature.

ps. We run all our APs in Flexconnect mode even if they only have centrally switched WLANs configured because that is a TAC recommended workaround for association timeouts which can (and do) happen when using MAC address bypass (MAB) when the site is remote and radius reply can sometimes take longer than the central association timeout.

[Rasika Nayanajith]

"PS: Not sure why c9800 is so complicated, Ubiquity and Omada are so simpler. The idea that I think is that I try to use enterprise gear in a very small setup and this where problems come up."

Yes it it true you have to have some learning about 9800 to get things right. It may not straight forward like other vendors you mentioned which are truly plug an play solutions.

However if you understand 9800 basic config flow (Policy tag, Site tag and RF tag), then it make things much clearer to you. See following blog post helps in that sense.

1. https://mrncciew.com/2022/06/30/9800-tags/
2. https://mrncciew.com/2023/01/21/9800-flexconnect-basics/

HTH
Rasika
*** Pls rate all useful responses ***