To create a route up to 192.168.23.254 (your main OVH IP), on an interface having no IP in this range, I use the commands:

route add -net 192.168.23.254/32 -iface em0
route add default 192.168.23.254  

The first line tell the firewall that IP address 192.168.23.254 is on the side of the em0 interface (em0 is my WAN interface), the second one use this address as the default gateway. Install shellcmd into pfSense and add the two commands above, this will make it survive a reboot. Adding more IPs Go to the firewall -> virtual IPs Add an IP Alias, add the IPs one at a time with a /32 Your IPs are now ready to use! LAN Internet Firewall -> NAT -> Outbound Manual Outbound NAT rule generation. If it isn’t created automatically add a rule with the Interface of WAN, source of your internal IP (192.168.1.x/24) leave everything else as default and save.