Networking - Static IPs
From Amahi Wiki
You can assign fixed (static) IP address to machines in your network, however, most modern machines will ask for a name to DHCP and that will work all the time regardless of the IP it gets.
However, if you need to set IP addresses, you can do it from the
Setup --> Networking --> Fixed IPs
And follow the prompts after pressing in the New Static IP.
You will need to enter:
A NAME for your device, that will be added to the Domain e.g. Laser_printer.home.com
An IP address in the range of 1-99, e.g. 192.168.1.20
The MAC address of the device (in the form 00:11:22:33:44:55)
Your client should remain set up as DHCP, but will be assigned this "Static" IP the next time it is rebooted or the DHCP lease is released/renewed.