[Kea-users] Dhcp6 crash with config-reload command v2.6.3

[Diogo André de Assumpção]

Thanks for the link, Darren. My lfc is set to 7200 seconds, and I can consistently repro the issue, so unlikely to be hitting that condition. That said, after I bumped the logs to debug I could see some better messages, which seems related to memfile-lfc:

2025-10-14 06:04:41.596 INFO  kea-dhcp6.dhcp6 DHCP6_CONFIG_COMPLETE DHCPv6 server has completed configuration: added IPv6 subnets: 4698; DDNS: disabled
2025-10-14 06:04:42.221 DEBUG kea-dhcp6.dhcpsrv DHCPSRV_CLOSE_DB closing currently open memfile database
2025-10-14 06:04:42.221 DEBUG kea-dhcp6.dhcpsrv DHCPSRV_TIMERMGR_UNREGISTER_TIMER unregistering timer: memfile-lfc
2025-10-14 06:04:42.221 DEBUG kea-dhcp6.dhcpsrv DHCPSRV_MEMFILE_LFC_UNREGISTER_TIMER_FAILED failed to unregister timer 'memfile-lfc': unable to unregister non existing timer 'memfile-lfc'

For reference, here’s what the lease section of my config looks like:

        "lease-database": {
            "type": "memfile",
            "name": "/var/lib/kea/kea-dhcp6.csv",
            "lfc-interval": 7200,
            "persist": true
        },


Thanks,
Diogo



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________________________________
From: Kea-users <kea-users-bounces at lists.isc.org> on behalf of Darren Ankney <darren.ankney at gmail.com>
Sent: Tuesday, October 14, 2025 2:01:36 AM
To: Kea user's list <kea-users at lists.isc.org>
Subject: Re: [Kea-users] Dhcp6 crash with config-reload command v2.6.3

Hi Diogo,

That backtrace doesn't look particularly useful because no symbols
were found.  Kea's logs would probably be far more useful in this
case.  it would have some message indicating why it is exiting.  Here
is one example of a problem you could be encountering:
https://urldefense.com/v3/__https://gitlab.isc.org/isc-projects/kea/-/issues/3986__;!!Bt8RZUm9aw!5lLpANoHvQQvKiYaNVp_snTIJEP7aIzeFRxARTJkRY0DpyQZ-bOuL5RS6BqpenRvmpHjAJR5IJJDBDxQ$<https://urldefense.com/v3/__https:/gitlab.isc.org/isc-projects/kea/-/issues/3986__;!!Bt8RZUm9aw!5lLpANoHvQQvKiYaNVp_snTIJEP7aIzeFRxARTJkRY0DpyQZ-bOuL5RS6BqpenRvmpHjAJR5IJJDBDxQ$>  but without log
messages, it is just guessing.

Thank you,
Darren Ankney

On Mon, Oct 13, 2025 at 6:15 PM Diogo André de Assumpção via Kea-users
<kea-users at lists.isc.org> wrote:
>
> Hi All,
>
> I’ve been experiencing an issue with kea-dhcp6 (4 doesn’t seem affected) where when I issue a config-reload command directly to the dhcp6 socket, the server crashes.
>
>
>
> Looking at the backtrace it seems to be related to the lease management – I’m using memfile – and maybe some cleanup that is done as part of the reload?
>
>
>
> Has anyone experienced something similar?
>
>
>
> Note that the config file loads fine when starting the server.
>
>
>
> Here’s a backtrace and a few more things from the coredump if it helps: https://gist.github.com/DiogoAndre/aa8c144329424b431b755711d7a96606
>
>
>
> Thanks,
> – Diogo
>
>
>
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