Non Active DHCP Static Reservation Given to New Device

[rhkg]

Good evening all,

I have been switching devices over to a new network configuration and just ran into something that had me scratching my head for a minute. I set up a device yesterday and as part of the setup made a static DHCP reservation for the device. Today, that device was powered off when I added a new device to the netowrk and the IP address for the static reservation I made yesterday was assigned to the new device.

Is this normal behavior? From what I understand, it is not, but someone may can correct my thoughts. I thought one of the reasons for a static DHCP reservation was so the static assigned address would not be given out to another device - under any circumstances.

If this is normal behavior, then is there a way (other than assigning static IP addresses to the devices) to make this work?

Running OPNsense 23.7.12_5. Yes, I know I need to upgrade to 24.1, but everything is stable right now and I am not going to chance breaking it until next year.

Thanks in advance for the help.

[Patrick M. Hausen]

Static reservations MUST lie outside of the dynamic range.

[rhkg]

Ok, maybe I am not using the right terminology here. What I am referring to as a static DHCP reservation is sometimes called a DHCP IP reservation.

Static DHCP reservation, also known as DHCP IP reservation, is a feature that allows a device to always have the same IP address when it connects to a network. This is useful when a device needs to have a consistent IP address, such as a printer, so that the computer can always find it.

I understand that static IP assignments that are set at the client need to be outside the DHCP dynamic range. What I am trying to do is get an IoT device that has no ability to use a static IP address to have the same IP address whenever it connects to the network and requests an address. So, if that is not a static DHCP reservation, then how to I do it?

Thanks again.

[Patrick M. Hausen]

See here: https://forum.opnsense.org/index.php?topic=44596.msg223063#msg223063

Assign your device a static address that is not also part of the dynamic range/pool.

[rhkg]

Ok, thanks much. Seems that this was just a misunderstanding on my part. Now that I have read up on it a little more, it actually makes a little more sense to me. I had wondered why the dynamic address was not automatically populated when a static reservation was created. I guess I know now.

Thanks for educating me. I am very new at the firewall and networking game. I am learning a lot, but sometimes it is slow.