An unusual situation prompted me to create a rather elaborate WDS configuration between three APs. Originally it was meant to be a simple AP with two clients, the clients would be configured as wireless bridges using WDS. However one of the two clients ended up not having good line of site back to the AP, so I had to get creative and create another WDS link that bounces of the other client, while preserving the important services...
Each AP/Client has three interfaces - 1 Ethernet, 1 CM9 and 1 SR5. Originally the SR5's where meant to connect to each other (AP/Clients) and the CM9's were there for backup/hotspot access. The Ethernet ports connect to the LAN/PPPoE network at each client site.
Basically I created a Virtual AP on the "Varsity" hotspot interface and turned on WDS, made it so that it adds WDS interfaces to the 'Backbone' bridge, which is shared with the ethernet and SR5 interfaces. This way the normal Hotspot AP can continue to function as normal although the interface will be under extra load.
Then on "The Village" hotspot interface I set its primary role to 'station wds' and created a VirtualAP to run its hotspot onto. This allows me to maintain the hotspot on this interface.
However the direct link back to the AP worked fine, so the link between the two clients was set up on STP for auto-failover.