Comment 3 for bug 1126560

Ok, with that config you should have all the scripts run twice in theory, once for the loopback device and once for eth0.
Not sure why you're seeing one running 3 times though.

All the .d scripts are run once per interface, so it's perfectly normal for them to be called multiple times. Interfaces are brought up as they show up from the kernel, so they can indeed be brought up in parallel. Scripts should expect that and deal with that accordingly. If they don't, a bug against the package providing the script is the way forward.