If AP's are on a different IP subnet then the Zone Director then you need to provide some way for the AP's to discover the Zone Director.
The Discovery mechanisms are:
- AP's on the same IP subnet discover the Zone Director and join automatically.
- You can configure the local DHCP server to provide the Zone Director IP using DHCP option 43
- You can configure a local DNS to respond to zonedirector.local.lan with the ZD IP. local.lan will be the domain provided by DHCP
- Manually configure each AP via AP CLI/SSH with the command: set director ip
- Depending on version, the AP GUI has a discovery option where you can configure the ZD IP into the AP.
All AP's initiate communication to the ZD's so AP's can work behind NAT, but you must be able to ping the ZD from the AP. The AP control protocol is lwapp which uses ports 12223 and port 12222. You also need port 21 (FTP) open to permit the AP to be upgraded from the ZD. Https (443) and Http (80) may be needed if you have guest services or captive portal configured.
Hope this helps,