On Wed 24 Jul 2024 at 14:29:34 (+0000), MailGuard01 wrote: > 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?
There is a bug report #960809, which seems related, and might be worth adding your experience to, if you think so. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960809 > 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. I did wonder whether any of the randomness wrt reboots might be time-related, as skim reading the RFC, it seems to allow for storing a history of addresses used, and periodic generation of new ones rather than a fresh one every reboot. Cheers, David.
