In all Sonicwall Firewall appliances, traffic from the wireless network (WLAN) to the wired network (LAN/DMZ) is blocked by default. As a result, when you run YAPI Mobile on your iPad even if you put correct YAPI Service IP address in Configuration, YAPI will not able to connect to Service and shows “Unable to connect” or “Connection times out” error.

To resolve this issue you need to allow traffic from WLAN Zone to LAN Zone changing  the default Deny rule to an Allow rule in  Access Rules (WLAN > LAN). Additionally you can restrict allowed traffic only to ports that YAPI is using  (TCP/UDP 18000, 18001,18002,18003) plus any other useful ports (it make sense to add port TCP 9100 used is LAN based printers so you can print from iPad)

This applies to SonicWall TZ 190, TZ 190 W, TZ 180, TZ 180 W, TZ 170, TZ 170 W, TZ 170 SP, TZ 170 SP Wireless, TZ 100, TZ 100W, TZ 105, TZ 105W TZ 200, TZ 200W, TZ 205, TZ 205W TZ 210, TZ 210W,TZ 215, TZ 215W, and PRO series.