[Kea-users] Expire single IP

[Darren Ankney]

Hi Ronald,

The identifier expression uses the classification expression logic
(see here: https://kea.readthedocs.io/en/kea-3.0.1/arm/classify.html#classification-using-expressions).
If you're client DHCP traffic is relayed, consider using the giaddr
(pkt4.giaddr) in the expression.

Thank you,
Darren Ankney

On Thu, Sep 4, 2025 at 8:38 AM DDFR | Ronald Blaas <ronald.blaas at ddfr.nl> wrote:
>
> Hi Darren,
>
> This looks very promising!
>
> Can we use this method per subnet ?
> Our DHCP server provides services for multiple subnets.
>
> Regards,
>
> Ronald
>
>
>
> ________________________________
> From: Kea-users <kea-users-bounces at lists.isc.org> on behalf of Darren Ankney <darren.ankney at gmail.com>
> Sent: Thursday, September 4, 2025 13:46
> To: Kea user's list <kea-users at lists.isc.org>
> Subject: Re: [Kea-users] Expire single IP
>
> Hi Ronald,
>
> Have a look at the flex_id hook
> (https://eur05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fkea.readthedocs.io%2Fen%2Fkea-3.0.1%2Farm%2Fhooks.html%23libdhcp-flex-id-so-flexible-identifier-for-host-reservations&data=05%7C02%7Cronald.blaas%40ddfr.nl%7C5a1dcd6ef3c24fce7cf108ddeba8ce9c%7C61b60fb772d74ba78225d9b5369d780a%7C0%7C0%7C638925832430964097%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=PNMBxikdl1Vu4%2BTR5eQJohhcRzGVyQlJgNEw%2B5o5m9k%3D&reserved=0).
> You can combine this with the replace-client-id flag
> (https://eur05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fkea.readthedocs.io%2Fen%2Fkea-3.0.1%2Farm%2Fhooks.html%23the-replace-client-id-flag&data=05%7C02%7Cronald.blaas%40ddfr.nl%7C5a1dcd6ef3c24fce7cf108ddeba8ce9c%7C61b60fb772d74ba78225d9b5369d780a%7C0%7C0%7C638925832431194932%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=0aKG0pGdkRiLes5YN7hSFRbwKvj%2BGQaPzkbSiu3KTOI%3D&reserved=0)
> so that the lease is recorded by option 82 as well (i.e., the
> client-id in the lease is replaced with the option82 hex).  In this
> way, Kea will effectively be unaware that the client has changed.
>
> Thank you,
> Darren Ankney
>
> On Wed, Sep 3, 2025 at 9:16 AM DDFR | Ronald Blaas <ronald.blaas at ddfr.nl> wrote:
> >
> > Hi all
> >
> > I was wondering if we could expire a single ip address after 1 hour (or maybe less)
> >
> >
> > The reason for this is we have a port on which we connect different devices but the same IP address (is assigned via Option82)
> >
> > With the IP address in the database it is locked so the second device gets an IP from the pool.
> >
> >
> > Ofcourse we can release the IP but I was wondering if this can be automated so the the IP is Expired sooner
> >
> >
> > Kind regard,
> >
> >
> > Ronald
> >
> >
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