This state allows to configure loopback device(s). This isn't meant to
be used in production but offers a cheap way to test Cinder with LVM
volumes.

This reverts commit a63f4053f3.

This patch replaces the "interface" collectd plugin by the "netlink" one. The
"netlink" plugin provides the same metrics as "interface" but plus other
metrics such as the number of dropped packets.

There is an error in salt doc. Hashing-alghoritm is correct, 90bbf8dc4f/salt/modules/debian_ip.py (L1045)