Cisco Switching/Routing :: AP1242G Forwarding Traffic From One Subnet To Another

I’ve configured a small WLAN for a school that wants to have wireless network access for their staff as well as for guests doing presentations. They want the staff to have access to everything on the 192.168.1.0 /24 network as well as the Internet. They want the guests to only have access to the Internet. I have attached a picture which shows how the network has been configured with 4 Cisco AP1242G AP’s attached to a Cisco SF302-08MP PoE switch and then to a Symantec Security Gateway to the Internet.
 
I can authenticate wirelessly to the STAFF SSID and ping anything on the 192.168.1.0 /24 network and access the Internet.I can authenticate wirelessly to the GUEST SSID and ping anything on the 172.16.1.0 /24 network, but not anything on the 192.168.1.0 /24 network (which is what we want). However, when on the GUEST network you can’t access the Internet. I added a default route to the Cisco 302-08MP switch to 192.168.1.1 (Symantec firewall) thinking that would forward the traffic from 172.16.1.0 /24 to the Symantec firewall out to the Internet, but that isn’t working.How would I go about getting the traffic from 172.16.1.0 /24 to hit the Symantec firewall and the Internet, without hitting anything else on 192.168.1.0 /24? Do I need to put the Symantec firewall in a different subnet like 192.168.2.0 /24? Am I missing anything else?I’ve worked with Extreme Networks & HP / 3Com CLI in the past, but never with Cisco and never with web based management