Hi,
Kea should be able to do just this using sanity checks:
https://kea.readthedocs.io/en/kea-3.0.1/arm/dhcp4-srv.html#sanity-checks-in-dhcpv4
but the default is "warn" so you would need to set:
"sanity-checks": {
"lease-checks": "fix"
},
It is recommended that you make a copy of all of this data in a test
lab and try there first.
Thank you,
Darren Ankney
On Tue, Oct 14, 2025 at 7:15 AM Per von Zweigbergk via Kea-users
<[email protected]> wrote:
>
> Hello!
>
>
>
> I am running kea in a 2-node HA cluster (hot-standby mode), with manually
> written JSON configuration and memfile lease backend.
>
>
>
> We’d like to migrate to using netbox-kea-dhcp to generate DHCP configuration.
> As far as I can tell from reading the source code, the tool works by
> generating configuration based on subnet ID being equal to the prefix ID in
> Netbox. (A prefix in Netbox is an object representing an IP subnet, and has
> its own ID.)
>
>
>
> This won’t work for us out of the box, because if we just blindly start
> creating subnet objects with prefix IDs that collide with our previous
> manually configured subnet IDs, the lease database will get confused.
> Therefore, as an intermediate step before implementing this sync, I would
> like to change the subnet IDs in my configuration, so the subnet IDs match up
> with the prefix IDs in Netbox.
>
>
>
> However, if I just change this in the config, we’ll get this lease database
> confusion. Therefore, my idea is to:
>
>
>
> In an outage window, stop both kea servers in the cluster to make sure the
> lease database isn’t being touched
> Change the JSON configuration to update the subnet IDs to the new desired
> subnet IDs, keeping note of the old ones
> Run some type of tool to change the subnet ID column of each rows to change
> from the old to new subnet ID (should be easy, it’s just a CSV file)
> Restart kea
>
>
>
> Before I go ahead and do this, I’d like some feedback from the community. Is
> there anything wrong with my approach? And is there an easier way of doing
> the same thing?
>
>
>
> (One thing to consider might be to de-couple kea subnet IDs from the netbox
> prefix IDs, and instead use user-context to store the netbox ID and do the
> mapping that way, but that would likely be more work than just doing the
> one-time operation above.)
>
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