When you are using DHCP to manage the IP address of your devices, then the settings of the devices must be on DHCP and not on Static IP.
DHCP is use to manage all IP address under its network. On the DHCP Server Settings you can assign or reserved IP Address on specific devices and constantly leases only for that machine address. It is the same goal with Static IP address to maintain its address without changing.
Network printers must have fixed IP Address and to achieve that, we usually make the network configuration of the printer in Static IP. All computers on the network can easily connect and remember the IP address of the printer.
I chose to set my printer on Dynamic IP address and let the DCHP Server leases the reserved IP on that printer constantly. This is likely same as having Static IP on that devices but this time it is being manage by DHCP server.
What is the advantage of setting your printer to be managed by DHCP?
DHCP is always the default network settings of the printer and it is easy as plug and play. It can easily join the network when you plug the cable or connect with the wifi.
Setting Static IP requires you to encode it manually in the setting and you have to know all the network details. It is not very efficient if you are setting on many devices. In a worst case you have to press the button to set it manually and cannot be done remotely. I am here in Philippines and I need to be in Singapore to set all the preferences. I don’t have to do that if it is auto configure by DHCP.
DHCP server cannot assigning dynamic IP to the device it the setting on the devices is set to static. It is important that the devices network configuration is set to DHCP.
There should be no problem in adding network printer with Dynamic IP address because the DHCP server is leasing reserved IP address for them.
You don’t need to configure all devices one by one to assign IP Address. Let the DHCP Server do all this work because it is built and design for that task.
How to Enable Manual Assignment or Reserve Dynamic IP address on Asus AC66U Router?
Log in to your router admin and go to LAN Settings
On DCHP Servers, you can see bellow Enable Manual Assignment and select Yes.
Add the Mac Address of the devices and put the IP address that you want to assign for them.
Save or apply the settings and reboot the devices to refresh and get its new IP address.