Is it possible to create a layout such as below. The site to site link is a fiber optic connection (we are given an Ethernet handoff from the provider). The problem seems to be routing the traffic over the interfaces that do not have an IP address. I know we can create a "bridge" subnet (say 172.16.1.0) and do routes to jump across but wanted to know if it's possible to get around that step.
#1 1720 FastEthernet0 (LAN to 10.1.1.0, IP: 10.1.1.1)
#1 1720 Ethernet0 (Site to Site Link)
#2 1720 Ethernet0 (Site to Site Link)
#2 1720 FastEthernet0 (LAN to 10.1.2.0, IP: 10.1.2.1)