Comment 4 for bug 964775

As I migrated from Lucid to Precise there was quite a bump when I realized that following lines:
auto eth0
auto eth1
would unsuspectingly have quite an impact on boot time if one of cables is currently unplugged.

Users who use mobile phones with auto/static configurations also have same problem when phone is not attached.

Clint Byrum gave some nice ideas for workarounds in https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/839595/comments/39

If you ask me as a user I would prefer to have seamless transition and expect same behavior from "auto".

However, introducing auto-nowait will also be not quite so obvious but nice/easy-to-use/grasp solution.

Please keep trying to make Ubuntu usable by mere mortals and thank you for your patience.