RED dhcp, static routed subnet and something like aliases


My provider only lets me dhcp the same address on WAN (RED)(always same address) and routes a /28 subnet via his backbone to that one address.

From the ipfire wiki I know that Aliases on RED are only possible with a static WAN addressing. In other firewalls I can use Aliases or virtual IPs on WAN/RED as well with my given net config.
How could I achieve the same or even a working config with ipfire, that I could use my static routed range? I do not yet know how to configure my networks in ipfire.

Many thanks

I made some tests and set my WAN address static, but routing of my dedicated ip range didnt work then. I verified with my provider,they mentioned that they do DHCP source verify incombination with the ip routing. Means that routing a static range will be only released if previously a DHCP ACK was successful. or so. For my scenario means I can not use my static ranges.