PowerDNS/pdns — pull request #1678 by mortenstevens (2014-08-22 10:13:53+00:00)
Title: use network-online target instead of just network

network-online.target is a target that actively waits until the nework is "up", where the definition of "up" is defined by the network management software. Usually it indicates a configured, routable IP address of some kind. It's primary purpose is to actively delay activation of services until the network is set up. It is an active target, meaning that is may be pulled in by the services requiring the network to be up, but is not pulled in by the network management service itself. By default all remote mounts defined in /etc/fstab pull this service in, in order to make sure the network is up before it is attempted to connect to a network share. Note that normally, if no service requires it, and if not remote mount point is configured this target is not pulled into the boot, thus avoiding any delays during boot should the network not be available. It is strongly recommended not to pull in this target too liberally: for example network server software should generally not pull this in (since server software generally is happy to accept local connections even before any routable network interface is up), it's primary purpose is network client software that cannot operate without network.

See: http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/