KeaDHCP dynamic DHCP question

[stauf]

Well good to know.  I was going to try to turn on Automatic Discovery and see if I could find a rogue ARP request on my network causing OpnSense to mis-behave like this, but, for now, I think I am good just leaving it off.  I, personally, don't really Automatic Discovery and it appears it does more harm than good at the moment.  Thanks for checking into it.

[FrankAusNRW]

Same issue here w/ OPNsense 26.1.4. ICS-DHCP is not installed anymore and DNSmask DHCP is disabled, so only KEA is running.
The DHCP range is going from .200-.249. All IP adresses in the DHCP range AND all unused IP addresses outside the DHCP range are blocked, even for inactive clients w/ fixed leases.
Effectively there is no chance for a client to obtain an IP address at the moment.
This is causing some trouble.

Is there a workaround or a fix in the near future?
If not, I need to get back to ICS or DNSmask DHCP for the time beeing.

The installation was a fresh ISO 26.1.2 installation.

[Monviech (Cedrik)]

I assume it would make sense to check the KEA logs then why it assigns these leases?

[stauf]

Frank,

For me, there seemed to be two workarounds and my "fix" was to disable Automatic Discovery.

1. Disable Automatic Discovery and wait.
2. If you need a solution faster, you can follow the instructions earlier in this thread.  SSH in (you may have to enable SSH), get into the shell and then go to /var/db/kea/.  There should be at least 1 .csv file in here.  Stop KeaDHCP, edit these files removing the incorrect entries.  This may take a few minutes to ensure you do it correctly as the files don't appear to be in order and there may be multiple (I had 2).  Restart KeaDHCP.  For me, I did this live.  I was stuck with all my addresses "in-use" so there didn't seem much harm to me doing it live.  Didn't appear to make anything worse.  Even with Automatic Discovery disabled, I did have to do this a couple times, but now, a couple days later, I see no erroneous entries in my cache.

As a side note, I did experience Automatic Discovery seemingly turning itself on once.  I had disabled and applied but then noticed it was on again sometime later.  I was never able to reproduce this so not sure what caused it.  I will just caution you to double check a few times that it is disabled, just in case.