WLC5508 Migration to 9800-40

[ifabrizio]

Dear All,

I am planning to migrate from the WLC 5508 with Airos 8.2.170 to the WLC 9800-40 with IOS XE Amsterdam 17.3.2a

I have 130 Access-Point that are working, the AP models are:

AIR-LAP1142N-E-K9

AIR-LAP1262N-E-K9

AIR-CAP1602I-E-K9

AIR-CAP2602E-E-K9

AIR-CAP2702E-E-K9

AIR-CAP3702I-E-K9

I know that starting from the top of the list, the first four AP are no longher supported by the IOS XE WLC, instead the last two model should be supported by IOS XE.(Could you pls confirm it?)

My question is about the migration strategy, I need that the AirOS WLC work in parallel with the new IOS XE WLC, so I see that Cisco offer a AirOs release the IRCM 8.5.164.0, that should permit to the old 5508 to connect via Secure Mobility Tunnel to the new 9800-40 and permit wifi clients roaming between the two wlc.

My question is it true? There are anyone that has some experiences about it?

The documentation that I found is contradictory, in this document:

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-8/b_c9800_wireless_controller-aireos_ircm_dg.html

The author says that:

"Cisco catalyst 9800 wireless controller uses CAPWAP based tunnels for mobility. The mobility control channel will be always encrypted and the mobility data channel can be optionally encrypted. This is called Secure Mobility.

AireOS uses EoIP tunnels for mobility. Support for CAPWAP based encrypted mobility (Secure Mobility) was brought in in 8.5. However the support for IRCM with Catalyst 9800 wireless controller is present only in 8.8.111 and above and in the 8.5 IRCM supported release"

What it means? I understand that the 5508 with 8.5.164 should be able to setup a SecureMobility Tunnel via CAPWAP with a 9800 wlc, is it right?

I also found another document that confirm it, I need to know If me undestanding is correct:

https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9800-series-wireless-controllers/guide-c07-743627.html#MigrationfromAireOSWLCtoC9800

Bye,

JF.

[Leo Laohoo]

Only the 2700/3700 will be supported.

[patoberli]

I think if you upgrade the 5508 first to the special IRMC build https://www.cisco.com/c/en/us/td/docs/wireless/controller/release/notes/crn85mr6_ircm.html 

roaming between the two controllers should be possible. Downside to this solution, various of your current APs will stop working once you upgrade. So for a "long" migration this might not be feasible.

So one upgrade path that I see, do building by building or at least floor by floor to minimize roaming issues. That way, you could put the management interface of the new WLC into a new VLAN and adjust the interface configuration of all APs on that floor. By using an adjusted DHCP option 43 in that VLAN, the AP might join the new WLC on reload. I am not sure if this will work though, so test it first. The AP should then load the new firmware and join the new WLC.

An alternate is to configure the new WLC in the high-availability tab of each AP as primary, once you do this and press apply, they start to switch to the new WLC. I never tested this with completely different firmware, like you are doing now. I did this to switch from 8.2.x to 8.5.x though and that worked. 

[Scott Fella]

I think you should focus on “if” it’s possible to migrate or “if” there should be a hard cut. The WLC matrix is the Bible to Cisco wireless and that will show what is compatible, model and code. You never mentioned what aps you will be migrating too, if you will replace all old existing aps or not? Mobility works between AireOS and IOS-XE as long as you are on the right AireOS code.
In your case with such a mix of ap models and some very old, I wouldn’t do a migration if I had a choice. You have to understand devices... devices will prefer AC aps over N which you already have in place and can cause clients to be sticky. Introducing WiFi 6 aps, can also cause WiFi 6 capable devices to prefer those aps over others. This will cause user experience issues. Now... swapping aps is okay, but and old design is and old design. Unless you already have good ap placements that provide overlap coverage, density and optimal roaming, then you should look at having a site survey done and adding, removing or relocate existing locations. There is always a budget you need to make a migration or new install work. Doing it right that does not cause user experience issues is the key. Also fixing what is currently broken or what users complain about is also another important point(s) to remediate. If you don’t remediate these issues or concerns, then the migration is a failure to users and the would never “trust the network” and will always “blame the network”.

[Grendizer]

I just posted details about that in here https://community.cisco.com/t5/wireless/interoperability-between-catalyst-9800-and-aireos/m-p/4273407