WLC9800 &9120 and reconfiguration of existing switches

[MR203]

Hi

I am trying to migrate from Cisco 5508 to new cisco 9800 WLC and new 9120 APs.  The goal is to gradually migrate to new APs network. Both old and new controller will be up for few days . After full deployment old WLc will be decommissioned. 

The current 3700 AP’s are connected to the existing Cisco Lan switches . New 9800 controllers will be connected to new switches . I will configure the new switches to support new WLC.

my question is for existing lan switches where the 3700 APs are connected , do I need to reconfigure those existing switches to support new 9120 access points ? Do I need to change VLAn on existing switch to support new APs? Basically touch all switches that will be used to connect new APs?

thanks

[balaji.bandi]

A couple of question required to ask here :

How is your Migration plan and SSID? Is the SSID going to be the Same?

they can co-existing same switch same Lan if you have any IP address issue, if not I would advise going with new VLAN new IP address, so you know where the device connecting easily to identify the issue ( again this go back to your Migration plan) 

Do you require existing WLC and AP connected and working along with new WLC 9800 and 9100AP running same time?

[MR203]

1- The plan is to migrate one building at a time . Total 4 buildings . Remove old APs , install new APs . Install new controller and core switches to support the new controller . 

2- the plans is to use same ssid . The old APs will be removed one building at a time . New APs will take over same ssid.

option1 :

I remove old APS one building at a time . Install new APs . The new APs can use same VLAns and SSID as old APs and there shouldn’t be a

any problem. I don’t need to reconfigure existing Cisco switches . Does this make more sense ? I am trying to avoid switch re-configure to support new APs 

[balaji.bandi]

If you removing OLD AP and installing a new AP ( check the weight of the AP. I had some situation where to fall ceiling fell off due to the weight of the AP) - check POE availability in the Switch and speeds.

Options 2 is the best option, make sure your DHCP option set up correctly for the new onboarding AP will reach the new controller.

Before cutover, test 1 or 2 AP onboarding process and SSID working as expected, where OLD AP not available - so you know where you connecting to new AP all working as expected.

[MR203]

Got it . No existing switches reconfiguration required right ?

[balaji.bandi · Accepted solution]

No, you do not need any configuration as long as you plugging in the same port and the same VLAN used, 

check any port security - since MAC is changing (OLD AP MAC to new AP MAC), it may have chances to block the port if the port configured security., so clear the arp for that port in case required.

Again test 1 AP you will know the process clearly and learn lessons from that process.

[saravlak]

to ans to your specific question,

9120 connected to new switches should have appropriate vlan(AP.mgmt), dhcp scope, routing to new wlc's mgmt ip and WLC L3 discovery mechanism in place.

for existing switches to support 9120 APs - Check the 9120 is supported by the switch model, if supported then you can use the existing config, however go through below notes.

Important Notes:
Make sure 3700 APs are Primary HA configured with old 5508 to avoid joining to new WLC 9800. Believe, you're replacing 3700 with 9120 and don't want 3700 AP joining new WLC because 9800 running 17.3.3 does support AP 3700.
5508 doesn't support 9120 so the new APs can't join in here.
you may want to configure new 9800 in global DNS or option43 after the migration is fully completed to avoid AP 3700 not configured as primary-5508 trying to join new WLC.
so manually stage all-new 9120s with new WLC as primary HA of the AP OR make sure none of the AP 3700(with no HA configured) have route access to new WLC's mgmt ip when new WLC configured for discovery.

Successfully clean deployed many aireos to iosxe migrations including infra/switch migration.