topic Re: WLC 9800 and 5508 best approach in Wireless

WLC 9800 and 5508 best approach

joseponceiii — Mon, 05 Jul 2021 20:02:20 GMT

Hello,

We have an old controller 5508 in HA that has couple of 3700s and 3500s AP and we have a new 9800 up and running. We know that the 3500 APs are not supported in the new 9800 and we are going to replace them with 9130 models. Now, there is an existing site that we use static to assign IP address to the APs in the old controller. What do you think is the best approach in getting the 9130 APs joining the new WLC.

Here is what I think as of the moment:

1) Configure via console the new 9130 APs (only few numbers so wouldn't hurt much) and assign the old 3500s AP IP addressing, gateway, hostname, and use the primary-base command to point to the new controller IP address.

2) Once statically configured, I'd expect the 9130 APs to join the new controller once rebooted.

1 and 2 above I'd expect to work just fine.

Now for 3700 APs to migrate little by little to the 9800, I'm also planning to do this approach for this specific site (still in static on old controller).

-SSH/Telnet to the 3700 APs and use the command primary base to point to the new controller, then reboot. Expecting to join the new controller.

-My question is, what if we want to revert back to the old controller, am I just use the same step? SSH / Telnet to the AP and use the command? Would you expect that to work?

Thanks,

Jose

Re: WLC 9800 and 5508 best approach

pieterh — Thu, 25 Mar 2021 09:36:07 GMT

you need not ssh into the AP? -> from the controller you can can configure primary controller on the AP.

my suggestion would be

- for the new wlc add entries in DNS, DHCP options etc so the AP's can discover this controller

- reset the AP to factory default and reboot

be aware ! the new 9800 will have a different image for the AP, so the migration may take some time

and when you need to go back, loading the old image also needs patience

Re: WLC 9800 and 5508 best approach

joseponceiii — Thu, 25 Mar 2021 09:46:51 GMT

Thanks for the reply. SSH is only an option aside from the controller GUI.

As for the old and new WLC, I'd like to retain the static setup and thus would not require the DHCP to give IP addresses to the APs. Option 43 would also be insignificant, correct? Would you think this would still work?

You're correct it will download from the old controller to the new controller image and vice versa.

Re: WLC 9800 and 5508 best approach

pieterh — Thu, 25 Mar 2021 11:18:39 GMT

I understand you have valid reasons for not using DHCP,
you are correct, if the AP does not send a DHCP request it will of course get no reply and so not receive option-43.

the method I suggested is the one i would prefer.
where the DHCP server does not need to be the WLC it can be any DHCP server in your network.

Re: WLC 9800 and 5508 best approach

patoberli — Thu, 25 Mar 2021 13:15:35 GMT

As you anyway want to login to each AP to set the IP address, set it's network configuration and also configure the primary WLC. It will then automatically connect to that one on next reload.

Alternatively, make a tiny DHCP pool of 1-4 addresses with short lease timeouts (and short re-use time) and there set the needed Option 43. That way you can just plug them in, they will connect with the WLC and you can configure it directly on the WLC, including fixed IP address.

Re: WLC 9800 and 5508 best approach

Rich R — Thu, 25 Mar 2021 14:42:19 GMT

My first thought was also - why are you using static IPs?

Now would be the right time to change your design to using DHCP.

But if you insist on staying static then you just make extra work for yourself in managing them. If you only have a few APs then maybe you're ok with that.

Also just to highlight: you're only planning to replace the 3500's but are you aware that 17.3 is the last 9800 release which supports the 3700's? That means you'll never be able to upgrade your 9800 past 17.3 without replacing the 3700's.

Obviously your choice but just be aware that features and AireOS parity are still being rapidly added to IOS-XE in every release so be quite sure that every feature you need is available/supported/working in 17.3 or earlier (test VERY thoroughly) otherwise you'll find yourself wanting to upgrade to get the feature support but not being able to because you still have 3700 APs.

We've already found plenty of things which don't work in current releases - some have clunky workarounds or we can manage without but others we're waiting for 17.5 or 17.6 before they're available.

And don't be fooled by the command just being available in IOS-XE command line - many of them are there but have no effect and are not supported yet.