When I conduct my classes on an isolated network, the first thing we need is a DHCP server.
The other option would be to statically configure an ip address on each device and risk typos and duplicate addresses. DHCP also becomes a huge benefit when working in a lab.
I have configured a few 8 port fanless Cisco switches with DHCP for these exact reasons.
In this video I walk you through how straightforward it is to configure a Cisco router as a dhcp server.