Hi Cristina,
You almost have it. What you want is to add a "client-class" (less
than 3.0) or "client-classes" (3.0+) guard to the pool.
This is simple as adding a line to your configuration:
subnet4 : [
{
“Id” :”1”
“match-client-id”: “false”,
“subnet”: “X.Y.Z.0/24”,
“pools: [
{
“pool”: “X.Y.Z.50 - X.Y.Z.252”,
"client-classes": [ "KNOWN" ]
}
]
“reservations-global” : false,
“reservation-in-subnet” : “true"
“reservation-out-of-pool” : “true”,
“reservations”: [
<?include “/etc/kea/static.json” ?>
<?include “/etc/kea/dynamic.json”?>
]
}
]
This demonstrates using the special class "KNOWN" as a guard
(requiring membership in the class or classes named in the list) on
the pool. Clients become a member of this class because they have a
reservation. These special classes are explained here:
https://kea.readthedocs.io/en/stable/arm/classify.html#built-in-client-classes
This method (guarding pool assignment by specifying a client class
that the client must be a member of) is covered here:
https://kea.readthedocs.io/en/stable/arm/dhcp4-srv.html#pool-selection-with-client-class-reservations
Some more related information in the ARM here:
https://kea.readthedocs.io/en/stable/arm/dhcp4-srv.html#host-reservations-as-basic-access-control
Thank you,
Darren Ankney
On Sun, Jan 18, 2026 at 9:51 AM Cristina Bulfon
<[email protected]> wrote:
>
> Ciao,
>
> Thanks for the answer.
> Maybe I described it incorrectly.
> What I would like is to configure a DHCP server that assigns IPs (I defined
> it as "dynamic" because there is no fixed correspondence between MAC and IP)
> only to a pre-established list of MAC addresses.
>
> Thanks,
> Cristina
>
> > On 18 Jan 2026, at 00:00, Francis Dupont <[email protected]> wrote:
> >
> > IMHO you do not need to create host reservations for "dynamic" clients
> > (and old versions of Kea required host reservations to have something
> > different e.g. a reserved address).
> >
> > Thanks
> >
> > Francis Dupont <[email protected]>
> >
>
>
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