On 15 October 2014 10:28, Trent W. Buck <trentbuck@gmail.com> wrote:
My impression is that Brian's talking about laptops that go walkies and
have multiple ifaces on the same net, which I guess is harder to magic
than a server, where you connect it up and then leave it alone forever.

There are a number of cases where it can get confused, not just laptops. 

For example, if you edit the network config and change a dhcp address to a static address, ifupdown won't kill the dhcp daemon for you.  Or if you change the static address to a dhcp address - ifup will complain the interface is already up, and IIRC ifdown will complain that the daemon is not running.

You are expected to shutdown the interface first, edit the configuration, then bring it up again. Which in turn increases the downtime.

Or there are plenty of times I have encountered where "ifup" fails while half complete, meaning "ifup" will no longer work (those tasks are already done), and "ifdown" won't work either (the interface isn't marked as up).

If you are working on a remote server, you want things to just work the first time, without fiddling around to try and ensure that ifup/ifdown are happy.

Having said this, I haven't installed/configured systemd-networkd yet, so I can'[t be certain it will fix these problems. Would be surprised if it doesn't however.
--
Brian May <brian@microcomaustralia.com.au>