Reserve a static IP address on an older Airport Extreme base station
What you could try is set the DHCP range to start at +1 and manually set the IPs on your server. For example, set the DHCP range to be 10.0.1.3 to 10.0.1.200. The 10.0.1.2 IP will be free to be used by your server. In AirPort Utility for me this is at Network > Network Options.