Even if you are using only bridged topologies on your WLAN, chances are you will need to access RADIUS (Remote Authentication Dial In User Service) servers, NTP servers, Syslog servers, DNS servers, DHCP (Dynamic Host Configuration Protocol) server for Relay, FTP servers for file and configuration backup management, and admin stations which may be several hops away from the controller. Also, the controller may need to be accessed by stations several hops from the network point of presence.
Routing configuration for the system is therefore strongly recommended and in most cases necessary. At a minimum the next hop default gateway that the controller interacts with to access these services should be defined.