It is best to configure the primary and secondary WLC in the high availability. This way if something happens and the ap joins the wrong WLC, it will move back. This is the issue if you keep option 43 enabled and or DNS resolution. If you want to make sure that AP's at a local site stays on that WLC, block udp 12222 & 12223 from crossing the wan. This way the AP's will not join the WLC at HQ. makes sense?
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