[arch-general] systemd-networkd and netctl with multiple interfaces

[Tinu Weber]

On Wed, Nov 11, 2015 at 16:06:18 +0100, Bennett Piater wrote:
> They have different metrics as per the example from the wiki.
> 
> However, no wiki article or manpage that I encountered explained what
> exactly the metric does. Could you explain that to me?
> 
> Cheers,
> Bennett
> 
> > If there are multiple default routes with the same metric, this might
> > cause issues, as packets might be sent randomly through one of the two
> > interfaces (thus with different IP addresses), leading to packet drops.
> > 
> > If the metric value is different, this shouldn't be a problem, though.

The idea is that if none of the routes match the destination, the
default route is used. If there multiple of them... well, nobody can
tell you what happens.

Usually the kernel chooses the route with the lower metric (to "break
the tie"), but I cannot tell you exactly what it signifies.

I'd suggest to try to find out why netctl makes it possible to have
multiple default routes (however, as I don't use netctl, I'm not able to
answer this), as this is usually a bad idea.

By the way, I'll redirect this discussion back to the mailing list,
maybe someone can answer this.

Best,
Tinu
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <https://lists.archlinux.org/pipermail/arch-general/attachments/20151111/37a4b755/attachment.asc>