When the dummy network driver is initialized with no parameters, a link
is automatically created (named 'dummy0'). This is inconsistent with
other virtual network drivers such as veth, macvlan, and macvtap, which
do not create a link upon initialization.
Actually, this is consistent with _other_ virtual network drivers such
as loopback, ifb, and teql, which create a link upon initialization ;-)
Jarek P.