The prefixLen for a loopback address is well-defined (/8),
and as such the variable is set accordingly.
Signed-off-by: Olivier Tilmans <olivier.tilmans@uclouvain.be>
Having an 'import mininet.node' in the link module causes
a circular import as the node module also has a top-level
import for the link module.
In order to break the cycle, the import for the node module
is delayed and executed only if using the sole class that
actually needs it in the link module.
In recent kernels, virtual interfaces come without any associated
qdisc, resulting in errors when spawning the network.
Checking for "noqueue" in the tc output, enables to detect that
case and thus avoid deleting the non-existent qdisc.