Re: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses
Hi,
@Kenneth , yes it is.
@Darren : thanks Darren for the “client-classes” tip ;-)
Ciao,
Cristina
> On 19 Jan 2026, at 01:14, Darren Ankney wrote:
>
> 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”: [
>
>
>]
> }
> ]
>
> 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
> 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 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
>>>
>>
>>
>> --
>> ISC funds the development of this software with paid support subscriptions.
>> Contact us at https://www.isc.org/contact/ for more information.
>>
>> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>> [email protected]
> --
> ISC funds the development of this software with paid support subscriptions.
> Contact us at https://www.isc.org/contact/ for more information.
>
> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
> [email protected]
--
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Re: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses
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”: [
]
}
]
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
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 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
> >
>
>
> --
> ISC funds the development of this software with paid support subscriptions.
> Contact us at https://www.isc.org/contact/ for more information.
>
> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
> [email protected]
--
ISC funds the development of this software with paid support subscriptions.
Contact us at https://www.isc.org/contact/ for more information.
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[email protected]
Re: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses
It sounds like you want a "MAC filter" that only issues IP addresses to known MAC addresses. The IP addresses need not be predetermined. Is that correct? *From:* Cristina Bulfon *Sent:* Sunday, January 18, 2026 at 6:51 AM PST *To:* Kea user's list *Subject:* RE: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses 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. -- ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. [email protected]
Re: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses
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 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 > -- ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. [email protected]
Re: [Kea-users] Configuring a subnet for both static and dynamic assignment for authorized MAC addresses
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 -- ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. [email protected]
