ISC DHCP static mappings active although ISC DHCP is not enabled?

[dieter42]

Some time ago i changed from ISC to KEA DHCP, including static mappings (Name/IP but also static ARP).
I kept the ISC configuration as is, but disabled ISC DHCP.

Recently i had to update one device to a newer one, keeping the name and the IP address in KEA DHCP, but changing the MAC address.
This worked out, until to the point i updated OPNSense with a reboot afterwards.

The new device failed, due to the fact that the former MAC address was taken.
Removing the static mapping in ISC DHCP and to be sure, flushing ARP cache, solved the issue.

Hence my question: Is the static mapping in ISC DHCP active although ISC DHCP is not enabled?

[dieter42]

Sorry, worth to mention it's OPNSense 26.1.9 amd64

[dseven]

There's a clue in the help text for that option: "Warning: This option persists even if DHCP server is disabled. Only the machines listed below will be able to communicate with the firewall on this NIC."

[dieter42]

I haven't marked the checkbox per interface.
Maybe that's the reason i haven't stumbled across the according note :-(

Instead i marked the checkbox per mapping.
Assume same clue is applicable here ..

Thanks a lot fort your fast feedback!

[dseven]

Ahh, I see. I would assume so too.

If you're committed to Kea, it might be a good idea to clear the ISC config (https://forum.opnsense.org/index.php?topic=52058.msg268107#msg268107) and uninstall the plugin.

[dieter42]

True, that's what i plan to do.