On Sat, Jul 06, 2024 at 12:09:09AM +0200, Pascal Hambourg wrote: > From: Pascal Hambourg <pas...@plouf.fr.eu.org> > Subject: Bug#875308: linklocal ipv6 addresses in debian-installer netcfg > To: Marc Haber <mh+debian-b...@zugschlus.de>, 875...@bugs.debian.org > Reply-To: Pascal Hambourg <pas...@plouf.fr.eu.org>, 875...@bugs.debian.org > Date: Sat, 6 Jul 2024 00:09:09 +0200 > User-Agent: Mozilla Thunderbird > > > > When entering link local ipv6 addresses with interface suffixes > > > as gateway during the network configuration in the debian installer, > > > the installer detects the address to be malformed. > > Why would you need to do this ? AFAICS entering the plain link-local IPv6 > address without the interface suffix creates the expected default route.
That's a common misconception. Since link local addresses are from the same network (fe80::/64) on all interfaces, a route pointing to a link-local address, such as the VERY common fe80::1, is ambiguous and therefore MUST be written like fe80::1%enp2s0 which D-I does not allow. In theory, on systems with only one interface, this could be omitted but it would break immediately when a second interface is added. At the time when the default gateway is entered, we are configuring ONE interface with its name already known, so D-I would be able to add the interface by itself automatically, but sadly it not only does not do this, doing so manually fails the buggy plausibility check that was implemented. While we're at it, on a system with more than one interface, does D-I allow to leave the default gateway field empty? Greetings Marc
