topic I would not design in this in Wireless

Roaming between AP Groups on same controller

diondohmen — Mon, 05 Jul 2021 13:04:16 GMT

Hi experts,

I have the following WLAN setup:

- 3 WLC's

- 10 floors

- 10 IP-subnet, subnet per floor

- 10 AP-Groups

Floor 0 AP_GROUP_0 SUBNET_0 WLC1

Floor 1 AP_GROUP_1 SUBNET_1 WLC2

Floor 2 AP_GROUP_2 SUBNET_2 WLC3

Floor 3 AP_GROUP_3 SUBNET_3 WLC1

Floor 4 AP_GROUP_4 SUBNET_4 WLC2

Floor 5 AP_GROUP_5 SUBNET_5 WLC3

Floor 6 AP_GROUP_6 SUBNET_6 WLC1

Floor 7 AP_GROUP_7 SUBNET_7 WLC2

Floor 8 AP_GROUP_8 SUBNET_8 WLC3

Floor 9 AP_GROUP_9 SUBNET_9 WLC1

Floor 10 AP_GROUP_10 SUBNET_10 WLC2

Every time a user roams from Ap on Floor0, to Floor3, L3 connectivity is gone.

The user first connects on an AP on Floor0, which is bound to AP-Group0 and IP-subnet0, travels to Floor3, the WLC will perform a intra-controller roam, and updates the AP entry in the MSCB table, but it'll keep the IP address. But, the AP-group on Floor3 is different, and so is the IP-subnet bound to it. So the user will try to communicate with it's old IP address (Floor0) within the new Ap-Group3.....

Is this working as designed and should I change my AP-Groups, or can I change this behaviour...

I suppose this would be a normal L3-roaming decision... and things should work out just fine?

"DHCP addr assigned required" option, will not work..

I would not design in this

Rasika Nayanajith — Mon, 31 Oct 2016 17:57:08 GMT

I would not design in this way. Near by floors should be go to same WLC to minimise the inter-controller roaming.

Also if possible create a large subnet and get rid of this subnet per floor design.

HTH

Rasika

Hi Rasika,

diondohmen — Wed, 02 Nov 2016 00:14:03 GMT

Hi Rasika,

Getting rid of the subnet_per_floor design would definately fix the problem. But, I don't want to enlarge the current subnets, so expanding the existing subnets is no option.

Best option would be an interface-group, and round-robin the clients within the different interface members. But then I will loose the mapping between user and floor.

What I would like to know; is this the way it works? Like, intra-layer3-roaming is not supported in this setup? Or, should it work in the way that when roaming between AP-groups, the IP address whould be updated also?

Client IP won't change depend

Rasika Nayanajith — Wed, 02 Nov 2016 00:14:04 GMT

Client IP won't change depend on the roam type (inter or intra controller) as long as smooth wireless coverage is there between floors.

Client IP determine by where the device get associate to wireless network in the first place (most of clients may get level 1 IPs if they come there first and then go upto other levels.

HTH

Rasika