Hi Gregor, You can safely use either one. When Kea encounters a subnet/pool for which 10.0.0.2 is not relevant, it will not assign the address. The client will instead receive a pool address.
Thank you, Darren Ankney On Mon, Nov 24, 2025 at 3:52 AM Gregor Kling <[email protected]> wrote: > > Hi Darren, > > On 11/21/25 4:38 PM, Darren Ankney wrote: > > Hello Gregor, > > > >> Hi Darren, > >> > >> Deciding the reservation model > >> > >> 9.3.9. Global Reservations in DHCPv4 describes in general our > >> setup. Clients generally can roam in our network based on the > >> attributed "pool class" to the specific mac address and the > >> "accessability" of the specific network. > >> > >> The following section: > >> > >> #+begin_quote 9.3.9. Global Reservations in DHCPv4: > >> An address assigned via global host reservation must be feasible for the > >> subnet the server selects for the client. In other words, the address > >> must lie within the subnet; otherwise, it is ignored and the server will > >> attempt to dynamically allocate an address. If the selected subnet > >> belongs to a shared network, the server checks for feasibility against > >> the subnet's siblings, selecting the first in-range subnet. If no such > >> subnet exists, the server falls back to dynamically allocating the address. > >> #+END_quote > > This is generally true, but you are not (as far as I understood) > > assigning an address to the clients in the reservation and instead are > > selecting a pool for them to use for a dynamic address with the > > reservation (by adding the client to one or more classes and using a > > class guard on the pools). > > Generally true - yes - but with the following exception. > > Again given the following setup. When the host with the > mac "a1:bb:cc:dd:ee:ff" visits his "homebase", > > subnet id 1 it should be given the "ip-address": "10.0.0.2" and not a > pool address. > > Should this host however visit, for example subnet id 2, it should be > given a pooladdress. > > So the the question remains (on this blurry monday morning) - which > reservation model should i use? > > #+begin_quote > { > "Dhcp4": { > "client-classes": [{ > "name": "pool_name_1", > "valid-lifetime": 3600 > }, > { > "name": "pool_name_etc", > "valid-lifetime": 3600 > }, > ], > "subnet4": [ > { > "id": 1, > "subnet": "10.0.0.0/24", > "pools": [ > { > "pool": "10.0.0.10-10.0.0.100", > "client-classes": ["pool_name_1", > "pool_name_etc"] > } > ], > "reservations": [ > { > "hw-address": "a1:bb:cc:dd:ee:ff", > "ip-address": "10.0.0.2", > "client-classes": [ "pool_name_1", "pool_name_etc" ] > > }, > { > "hw-address": "a2:bb:cc:dd:ee:ff", > "ip-address": "10.0.0.3", > "client-classes": [ "pool_name_etc" ] > > } > > ] > }, > { > "id": 2, > "subnet": "192.0.3.0/24", > "pools": [ > { > "pool": "192.0.3.10-192.0.3.20", > "client-classes": [ "pool_name_1" ] > }, > ], > "reservations": [ > { > "hw-address": "a1:bb:cc:dd:ee:ff", > "client-classes": [ "pool_name_1", "pool_name_etc" ] > > }, > { > "hw-address": "a2:bb:cc:dd:ee:ff", > "client-classes": [ "pool_name_etc" ] > > } > > ] > > } > ] > > } > > } > > #+end_quote > > > -- > > Gregor Kling > > Abteilung ITS, Sachgebiet ITS-N > Technische Hochschule Mittelhessen > University of Applied Sciences > Tel: 0641/309-1292 > E-Mail: [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] -- 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]
