Setting nic address and default gateway as the same ip

  • Hi everybody,
    i have recently added a new wan (the third) to my network, but the ISP wants some strange configuration.
    The situation is:
    WAN subnet is is the ISP router addres are 16 ips tha my ISP map 1:1 to 16 public ips.
    i've got a new wan interface on pfsense whilch have address
    The problem is that my ISP wants that every machine that take one of theese 1:1 mapped addresses
    is set up with a default gateway which is the same ip address as the nic address, otherwise they don't let me access the internet.
    I want to assign theese 16 ip to machines that are on a DMZ ( so i've got 16 virtual ip and 16 corresponding nat 1:1 on my pfsense box but i don't know how to asign them a different default gateway as my provider wants, because they all have set pfsense DMZ interface address as default gateway.

    i've heard that this configuration was largely used for dial-up connections
    but i don't know how to adapt it to a pfsense managed network
    What can i do?
    thanks everybody for help