WLC do Primary & Secondary Controller Network locations

[russellra]

On WLC > Wireless > AP > High Availability, do the controllers have to be on the same LAN? In other words, can they be located across a layer 3 boundary, say in different geographic location?  I don't see how Secondary WLC can support an AP that not configured 'locally' (local interfaces, WLAN, AP group, etc.).  H-REAP presumably.  I configured many of those and they work great (local switching).  My understanding is that an LAP *must* be local with an interface, WLAN, AP group, and a local Vlan trunked to the WLC interface.  Can somebody clarify this for me? Thanks.

[Scott Fella]

You can have wlc across the WAN, the thing is, what ip address will the devices get.  AP's will failover to any WLC that is on the same mobility group and is reachable so that isn't really the issue.  You have to look at what happens when an ap joins the other wlc, and the ap is in local mode.  The traffic will be placed in that local network and devices will have to obtain a new dhcp address in order for them to have network connectivity.  Static address devices will not work in this scenario.  H-REAP local switching doesn't matter since the traffic is local where the ap is.  H-REAP centrally switched will have the same issue since the wlcs have interfaces in different subnet's.

Thanks,

Scott

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[Saravanan Lakshmanan]

AP join happens using control plane, as long as AP HA has Primary, Sec controller's name and IP info and have L3 reachability to those HA WLCs(from AP's IP at the remote site) failover happens without an issue. The locally switched wlan mapped to vlan is per site basis.

For hreap, AP holds the WLAN to VLAN map config for locally switched wlan unlike central switch wlan mapped to dyn int of WLC.

It is my suggestion -fail the hreap APs atleast once to all HA WLC before production so that all WLCs can learn the AP config to avoid AP's being mapped to default vlan.