[systemd-devel] Systemd-networkd, default route and multiple interfaces

[Mantas Mikulėnas]

On Tue, Jun 3, 2014 at 9:58 PM, Lennart Poettering
<lennart at poettering.net> wrote:
>
> On Mon, 02.06.14 21:02, Tom Gundersen (teg at jklm.no) wrote:
>
> > On Mon, Jun 2, 2014 at 8:47 PM, Reventlov
> > <contact+systemd+ml at volcanis.me> wrote:
> > > Since network files are applied to links whenever the links
> > > appear, how do systemd manage the "disappearance" of a default route ?
> >
> > You can have several default routes, so we just configure them all and
> > let the kernel handle it for us. We probably should improve the config
> > options to make it possible to override the priority of the routes.
>
> Windows initializes the route metric value for each route from the
> "speed" of the interface. If there are multiple links and for one we
> know it's a gigabit ethernet link, and the other is a 54mbit wlan link,
> then the former would automatically get preference... it's a bit black
> magic, but kinda cool black magic i think...
>
> that said, i am not sure we even have a sane API to determine the speed
> of links... maybe ethtool reports it at least for wired ethernet? but
> for wlan?

Both `iwconfig <dev>` and `iw <dev> link` report the link speed (one
using the old wext and the other nl80211, I think?).

No idea about all the other link types that Linux supports though.

-- 
Mantas Mikulėnas <grawity at gmail.com>