Hi all,
I am trying to complete the network configuration on Debian 12 using the default
installed `ifupdown` package. I have noticed some confusing behavior with
`ifupdown` while following the manual pages.
Specifically, when I place `iface eno1 inet6 auto` with `privext 2` after `iface
inet eno1 dhcp` as instructed by the manual, the behavior becomes unpredictable.
Typically, the `privext` setting does not work as expected and has no effect
when I initially boot into Debian 12 every time, even though the value of
`/proc/sys/net/ipv6/conf/eno1/use_tempaddr` is correctly set to 2. No temporary
IPv6 address is assigned to the interface.
However, if I restart the networking service using `systemctl restart
networking`, everything starts working correctly, and the temporary IPv6 address
is assigned and displayed. Strangely, after multiple reboot of my Debian 12 PC,
the temporary address occasionally appears without manually restarting the
networking service. The behavior seems unstable and inconsistent.
When I accidentally placed `iface eno1 inet6 auto` with `privext 2` before
`iface inet eno1 dhcp`, everything worked without any problem. All settings
correctly applied, and there was no need to manually restart the networking
service.
I have searched online but found nothing relevant, as if this is an isolated
case. The manual also does not mention this behavior. I can reproduce this
consistently from Debian 11 to Debian testing/unstable.
Is this behavior expected / considered a feature? Or is it an isolated case?
Should I report this as a bug, and if so, where should I do that?
Additionally, it would be helpful to mention this behavior in the manual pages
if it's expected, perhaps in a known limitations section. It took me days to
solve this issue, and I was stumble upon the solution by sheer luck.
Any suggestions would be appreciated.
Best regards.
PS: I am not sure that I subscribed to the mailing list correctly as this is my
first time using one. Please forgive me if I did anything wrong. :>
Here are the full configuration I mentioned before. The default lo section is
omitted.
# privext will not work
allow-hotplug eno1
iface eno1 inet dhcp
iface eno1 inet6 auto
privext 2
# =====================
# privext works
allow-hotplug eno1
iface eno1 inet6 auto
privext 2
iface eno1 inet dhcp
