Wireless Transformation

[Ravichandra T]

Hello All,

Current Setup:

3502 & 3702 APs ==> Access Switch 3850 with Mobility Controller ==> 5508 WLC.

Proposed new setup:

3802 APs ==> Access Switch 3850 with mobility controller ==> 5520 WLC (Phase-1)

3802 APs ==> Access Switch 9300 ==> 5520 WLC (Phase-2)

Now the question is that 3802 can be independent of Access switch(planning not to use Mobility Controller feature) so that it can be controlled by 5520, as old APs will be replaced with new ones with parallel 5520 controllers, so looking to register new APs with new WLCs. Will there be any challenges ?

[Scott Fella]

That is a typical migration from 5508 to 5520 or even another model.  Just make sure you have mobility defined between the two and make sure you have everything setup on the new 5520 so that when you start your migration, devices connect fine.

[Ravichandra T]

Hi Scott,

Thanks for quick reply. Can I bypass MC on 3850 (kind of pass-through mode), so that new AP 3802 has to be controlled by new WLC 5520(Phase-1 plan), so that no dependency on 3850 switch for AP to WLC communication. Phase-2 plan is to replace 3850 with 9300 switches at latter, so that phase-1 connectivity should not be disturbed. 

[Scott Fella]

You diagram shows an existing 5508?  Are you using the switch with Converged Access?  That might be a bit difficult since Converged Access is no longer supported.

[Ravichandra T]

Sorry, lost with the wind for some time  ...Yes, in current setup 3850 switches with converged access is used. So now for phase-1 deployment..initially access points will be replaced and then new parallel WLCs will be deployed along with older ones...Now then question is how to reconfig APs to new WLCs via pass-through mode. New APs connected to 3850 switches in Phase-1. Once Wifi works with Centralised WLC, just switches will get swapped from 3850 to 9300..Appreciate your help on this !!

[patoberli · Accepted solution]

I would put the new APs into a new ap management vlan which is not serviced by converged access (CA), only by the new WLC. Then make sure your new WLC are working fine and all VLANs etc. are in order. Test this with 2-3 APs in the new VLAN serviced by the 5520.

I'm not sure, but I think there is probably no mobility between the CA and WLC if you run 8.5 or even 8.10 (which I recommend, if you only have 3700 and 3800 APs). 

https://www.cisco.com/c/en/us/td/docs/wireless/compatibility/matrix/compatibility-matrix.html#pgfId-393627

You could run 8.3.x on the new 5520, that would even allow mobility plus has support for all your APs. 

So by thinking again about this, I would probably run 8.3.x on the WLC and the latest supported code on the CA. That way you have working roaming between the new and the old world (with some restrictions probably). 

Once you have migrated, upgrade to the latest 8.10 release.

One important question though, why the 5520? If this is a new setup, don't buy it, because the end of life is already announced and software 8.10.x is the last release train and will receive for 1-2 more years updates. After that the 5520 will not anymore get any updates!

If you can, get a Catalyst 9800 WLC and make a hard migration (floor by floor or building by building). There won't be any roaming between the old and the new world, but if you do this floor by floor you should be mostly fine. You should not delay the replacement/reconfiguration to much though, because the experience will not be great.