[systemd-devel] [PATCH] Added UFD (Uplink failure detection) support to networkd

Lennart Poettering lennart at poettering.net
Tue Jan 27 13:26:24 PST 2015

On Tue, 27.01.15 19:54, Tom Gundersen (teg at jklm.no) wrote:

> Hi Alin,
> Thanks for working on this.
> I think the main concepts here make sense, but I have some comments on
> the implementation.
> So the main ideas are:
> 1) a notion of groups of links
> 2) a notion of up- and downlinks
> 3) configuring downlinks if and only if at least one uplink in the
> group has a carrier
> Comments:
> Maybe we should not restrict the naming to "UFD", as the grouping may
> be useful for other things in the future (would be great if you could
> comment on Holger's email for instance). In fact Lennart suggested we
> introduce the concept of 'tags' instead of groups, and these will be
> similar to tags in udev rules.

Taking this one step further we could even simplify further: maybe the
entire concept of tags our groups is unnecessary. Instead, let's just
introduce a single new setting:


Which takes a list of interface names, and supports globbing. Now,
with this functionality in place, and a good naming regime we could
implement such uplink/download behaviour too, right? I mean, let's say
you name all your uplink interfaces uplink0, uplink1, uplink2, and
your downlink interfaces downlink0, downlink1, and so on. Now, in the
.network file for the downlink, we'd simply say "BindCarrier=uplink*",
which would then mean that the port is only configured if at least one
interface matching that name, with a carrier is found.

Alin, wouldn't this be sufficient for you? I kinda prefer this
solution due to its simplicity, and as it does not introduce any new
concepts, and only a single new setting...


Lennart Poettering, Red Hat

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