I'm not use whether this is caused by ifupdown or bridge-utils. Please reassign if necessary.

Having just upgraded from Bullseye to Bookworm, I noticed that the behavior has changed once again, when it comes to whether interfaces conncted to a bridge have their own IPv6 link-local or not.

In Bullseye, Ethernet cards did not have any IPv6 local-link, while Wifi adapters did. In Bookworm, it the opposite.

It should be neither. Only configured interfaces should have an IPv6 local-link. For bridges, it means that only the bridge should have an IPv6 local-link, not the interfaces attached to it.

Martin-Éric

- -- System Information:
Debian Release: 12.0
  APT prefers testing-security
  APT policy: (500, 'testing-security'), (500, 'testing-debug'), (500, 'stable-security'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-9-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=fi_FI.utf8, LC_CTYPE=fi_FI.utf8 (charmap=UTF-8), LANGUAGE=fi:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages bridge-utils depends on:
ii  libc6  2.36-9

bridge-utils recommends no packages.

Versions of packages bridge-utils suggests:
ii  ifupdown  0.8.41

- -- Configuration Files:
/etc/default/bridge-utils changed:
BRIDGE_HOTPLUG=yes
BRIDGE_DISABLE_LINKLOCAL_IPV6_ALSO_PHYS=yes


- -- no debconf information
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Wifi is very dependant on how you configure it, but as you say, now on
bookworm you are not getting IPv6 on them, so... let's go for ethernet
cards... on my machines I don't see any inet6 address assigned to any of the
ethernet ports asigned to the bridge ports either full physical or vlan
based.

I agree on this, can you share your setup so that I can try to replicate it?

Also... is there any Router Advertisement Daemon or dhcpV6 daemon assigning
ipV6 addresses?

Regards...

Odd.

allow-auto br0
allow-hotplug /en* /wl*
iface br0 inet static
    bridge_ports regex (enp3s|enp2s|wl).*
    address 172.16.1.1
iface br0 inet6 auto
    # IPv6-PD via /etc/dhcpcd.conf
    # Routing via /etc/boot.d/iptables_IPv4-MASQ_IPv6-Bridge
iface enp4s0 inet dhcp
iface enp3s0 inet manual
iface enp2s0 inet manual
iface wlx(redacted) inet manual
    hostapd /etc/hostapd/hostapd-1-2G-wlx(redacted).conf

dhcpcd delegates the IPv6 prefix to br0:

allowinterfaces enp4s0 br0
require dhcp_server_identifier, domain_name_servers, routers
slaac private temporary
duid
noipv4ll
reboot 0
waitip 64
interface enp4s0
  ia_pd 0 br0

Martin-Éric

Can you remove these two lines (enp2s0 and enp3s0 definitions) and see if
that makes any difference?  I don't expect that will make any difference but
for what I see they are not needed.

Also... I'd add a "bridge_ports none" statement to the br0 inet6 stanza so
that it is handled by bridge-utils, otherwise the bridge won't do a thing
about it and maybe it is even showing some kind of error because of this.

Regards.

On Wed, Jun 7, 2023 at 10:43 AM Santiago Garcia Mantinan <manty@debian.org> wrote:

No difference.

No difference either.

Martin-Éric

On Thu, Jun 8, 2023 at 6:42 PM Martin-Éric Racine <martin-eric.racine@iki.fi> wrote:

In addition to Ethernet cards having an IPv6 local-link but WiFi
dongles not having any, another noticeable change in the output of 'ip
a' is that WiFi dongles are loaded after the bridge. In Bullseye, all
available devices were loaded by ifupdown before the bridge was
created.

Martin-Éric

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