Can i use untangle as bass by - web filtering

HI,
my scenario is that i have a firewall with 4 Eth interfaces as below :

Eth0: connected to the Internet or ISP
Eth1: programmed for (VLAN 11) VoIP, Connected to manageable switch.
Eth2: programmed for (VLAN 10 and 18) Servers and DMZ, Connected to manageable same switch.
Eth3: programmed for (VLAN 12) Clients, Connected to manageable same switch.

see the attached diagram for the network scenario.

could you please suggest where i need to fix Untangle ?

Attached Images

network.jpg (88.5 KB)