Yes, it is probably not possible for the device to store the DUID value so it generates it on every power-on. Only the MAC part of the DUID is constant. If kea does not put reservation into lease, all the problems would be gone.
Marek Sent with Proton Mail secure email. On Friday, November 29th, 2024 at 10:53, Marcin Siodelski <mar...@isc.org> wrote: > If the client keeps changing it DUID the Kea server has no way to tell > whether it is the same client that gets back or a different client. > That's why it would offer a different IP address assuming it is a > different client. > > Having said that, the DUID is a client unique identifier and SHOULD be > stable as the DHCPv6 spec says: > > https://datatracker.ietf.org/doc/html/rfc8415#section-11 > > " > > That is, the DUID used by a > client or server SHOULD NOT change over time if at all possible; for > example, a device's DUID should not change as a result of a change in > the device's network hardware or changes to virtual interfaces (e.g., > logical PPP (over Ethernet) interfaces that may come and go in > Customer Premises Equipment routers)." > > Marcin > > > On 29.11.2024 10:45, Marek Greško wrote: > > > Hello, > > > > I found out the problem source. It seems it is not achievable what I am > > trying to do. It works for the first time. The kea matches the DUID-LL and > > creates lease with full DUID. Then when the DUID changes, when the client > > tries to get the ip address, kea finds out the reservation address is > > already assigned to different DUID and offers IPv6 address from the pool > > then. So it seems the concept of storing reservations into the leases is > > not very mature. Or am I missing something? Is there some way to overcome > > the issue? > > > > Thanks > > > > Marek > > > > Sent with Proton Mail secure email. > > > > On Friday, November 29th, 2024 at 10:04, Marcin Siodelski mar...@isc.org > > wrote: > > > > > Marek, > > > > > > Have you configured MAC sources correctly? Since you're using MAC > > > address as host identifier you should also instruct the server where to > > > get the client's MAC address from. This is achieved by listing MAC > > > sources as described here: > > > > > > https://kea.readthedocs.io/en/kea-2.6.1/arm/dhcp6-srv.html#mac-hardware-addresses-in-dhcpv6 > > > > > > Note that one of the sources can be DUID-LL. So you can do this: > > > > > > "mac-sources": [ "duid" ] > > > > > > If nothing else you should also just be able to specify DUID-LL directly: > > > > > > { > > > "hostname": "host", > > > "duid": "03:01:01:02:03:04:05:06", > > > "ip-addresses": [ "fc00::7" ] > > > } > > > > > > I am not sure what exactly is changing in this client's DUID, though. > > > Isn't DUID-LL stable for this client? > > > > > > Kind Regards, > > > Marcin Siodelski > > > ISC > > > > > > On 29.11.2024 09:10, Marek Greško via Kea-users wrote: > > > > > > > Hello, > > > > > > > > I have working kea dhcpv6 setup. I am struggling with one problem. All > > > > my devices get correct IPv6 addresses from reservations by matching > > > > DUID. But one of the devices in the network have changing DUID, only > > > > the DUID-LL part is constant, so I tried to match on DUID-LL. I am > > > > convinced it was working before, but I cannot verify now. Nowadays I > > > > observe the device is getting the IPv6 address from pool. Not from the > > > > reservations. > > > > > > > > My config contains: > > > > > > > > "host-reservation-identifiers": ["duid", "hw-address"], > > > > > > > > and the reservation itself: > > > > > > > > { > > > > "hostname": "host", > > > > "hw-address": "01:02:03:04:05:06", > > > > "ip-addresses": [ "fc00::7" ] > > > > } > > > > > > > > The addresses are example one, not the real. What could be the > > > > problem? I tried to delete the lease from the leases file and restart > > > > the kea, so it is not the lease before reservation problem, but the > > > > lease was again offered from the pool. > > > > > > > > Thanks > > > > > > > > Marek > > -- 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. Kea-users mailing list Kea-users@lists.isc.org https://lists.isc.org/mailman/listinfo/kea-users
