Jail NAT how to assign a static IP

[binaryscary]

Hello everyone, I am trying to figure out how to configure a private static IP address for a Jail behind host NAT? I have a handful of NAT'd jail services communicating with each other, but upon each reset their private IP addresses change. The only other option I can see is setting them all to DHCP, but I don't really want unnecessary IP addresses filling up my network, if anyone have a solution they could share that would be great, Thanks.