Hi,
People are using Static or default route with natting.
router {Eo}---> {Outside}Firewall{Inside}--> Access or Distribution switch.
Router: Default route to ISP
E0 natting indide
Firewall : Acl and Nat on inside to outside for both subnets.
Switch id L3/Distribution: Point to inside firewall
If L2 / Access: Create two Vlan - and connect it.
Regards,
Dharmesh Purohit