I would like some clarification on the Mobility groups behaviors. We have 2 WLC 4402 (wlc-a and wlc-b) setup on the same DMZ and 30 AP connecting to the first one (wlc-a). We have setup the same mobility groups on both WLC. AP failover betwen the WLC works fine: if wlc-a disappears all APs go to wlc-b. But the connected clients suffer from this transition (using webauth, dhcp is provided by the wlc). We triied a couple of configuration options but are still facing the same issues at the end.
1- we tried to configure 2 different dhcp pools for the users. When wlc-a fails, APs moves to wlc-b (good), but client needs to negotiate a new IP and therefor looses any existing connections.
2- we tried to configure the same DHCP pool on both WLCs. Obvioulsy this is not a good idea as you end up allocating the same IPs to different clients.
3- we tried to configure the same DHCP on both WLCs and created an anchor to wlc-a. This works fine if wlc-b fails, the transition is seamingless for the clients. But not if wlc-a fails, wlc-b "refuses" to give an IP to the users.
I'm a bit puzzled by the problem and can't find what I'm missing. I was thinking that the two wlc would be able to provide (near) transparent failover for the clients (at least they should not have to get a new IP and reauthenticate).