Question on Interface Groups and Mobility

[cnegrete]

Hi everyone.

I have a small question.

I have two 5508 controllers with 6 Access Points (3 on each controller).  The network layout has one AP on one controller, one on the other, 45 degrees and about 100ft apart from each other.

In this layout the clients roam from one AP to the other, one controller to the other, but there are certain times where the client loses connectivity to the network (layer 3). I don't see any disconnect or roaming messages in the controller logs, but the laptop shows a "!" sign in its wireless connection (win 7).

It can take from a few seconds to several minutes for it to get an ip address and connectivity again.

Now, for my setup:

I have 3 interfaces with different VLANs, and an interface group that binds those 3 interfaces together. The interfaces are called the same on both controllers, and the interface group as well.

The wlan number is the same, as the SSID configuration.

The question is:

When the client roams to the other controller, does it retain the same interface/VLAN configuration?  I have found documentation stating that when the user roams and the WLC has the same subnet, it goes with no issues, but it doesn't mention interface groups.  Could it be that in some handovers the client falls in a different VLAN even when it is in the same interface group?

Thanks in advance for your help.

[Rasika Nayanajith]

Are these two WLC in same mobility group ? If that is the case clients should not change the IP when they roam from one WLC to another. Even in interface group configuration it should work like this.

Here is sample config I did to test this out (I haven't use interface group, but as per my understanding It should not make any difference).

http://mrncciew.com/2013/03/17/l3-inter-controller-roaming/

HTH

Rasika

[cnegrete]

They are in the same group, and I know that it does work with interfaces in the same vlan on two controllers, but I'm trying to pinpoint an issue and I'd like to know if there's documentation on this matter.

The two controllers are in the same area, they're even connected to the same switch, sharing vlans.