Comment 3 for bug 1269921

/etc/init.d/networking restart and "sudo restart networking" aren't supported ways of restarting the network, actually, we don't support any way of bouncing the whole network config as it's configured through event based bringup.

Rather than copy/paste half the code of ifenslave, could you instead post your current /etc/network/interfaces as well as the output of "ifdown -a -v" and "ifup -a -v"?

As a reminder, ifupdown is entirely sequential it's therefore required for the ordering to be roughly:
 - loopback
 - primary physical interface (bond member)
 - any other physical interface (bond member)
 - bond interface
 - any virtual interface (vlan, bridge, ...) based on top of the bond

If the interfaces aren't listed in precisely that order, "ifup -a" will hang (though the boot itself won't as it's using events to bring up individual interfaces rather than using ifup -a).