Bug#1076432: systemd: [networkd] incorrect IPv6 address generation

[Martin-Éric Racine]

Please note that if you only reply to the bug itself, the reporter
will never know that you requested more information.

On Tue, 16 Jul 2024 11:37:43 +0100 Luca Boccassi <bluca at debian.org> wrote:
> Control: tags -1 moreinfo
>
> On Tue, 16 Jul 2024 13:29:36 +0300 =?utf-8?q?Martin-=C3=89ric_Racine?=
> <martin-eric.racine at iki.fi> wrote:
> > Package: systemd
> > Version: 252.26-1~deb12u2
> > Severity: important
> > Tags: ipv6
> >
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA256
> >
> > I have enabled networkd and created the following
> /etc/systemd/network/dhcp.network:
> >
> > [Match]
> > Name=en* wl*
> >
> > [Network]
> > DHCP=yes
> > IPv6PrivacyExtensions=yes
> > IPv6LinkLocalAddressGenerationMode=stable-privacy
> >
> > Two issues:
> >
> > 1) networkd creates a new link address with the stable-privacy flag,
> in addition to the existing one created by the kernel on bootup.
> > 2) Regardless, the stable-privacy flag is not inherited by the
> mngtmpaddr address. It steadfastly uses an EUI64 address.
>
> Can you reproduce in testing/unstable?

Yes. It still ignores the fe80 created by the kernel at boottime with
the stable-privacy flag, it still creates an additional one, and it
still creates a public address with EUI64 instead of stable-privacy.

Martin-Éric