YazDHCP YazDHCP v1.2.4 [2025-Nov-21] - Feature expansion of DHCP assignments (increasing limit on the number of DHCP reservations)

[dave14305]

I did indeed mean that clients whose MAC addresses I have not registered should be excluded drom any connectivity.

From dnsmasq man page:

When a host matches any --dhcp-host directive (or one implied by /etc/ethers) then the special tag known is set. This allows dnsmasq to be configured to ignore requests from unknown machines using --dhcp-ignore=tag:!known.

So if you’ve assigned all your desired hosts a manual/reserved IP, you might be able to ignore any others by setting dhcp-ignore=tag:!known in /jffs/configs/dnsmasq.conf.add. Never tested it, but might get you closer to what you want.