Running command at startup on crontab

A few notes here before this would work:

1. Don't use sudo in a cron job. Instead edit root's crontab instead of your own, e.g. sudo crontab -e and then enter commands without sudo.
2. As @mikewhatever mentioned, this is an odd use for cron, and would likely be better placed in /etc/rc.local before the exit 0 line.
3. If you tell us exactly what you're looking for, we might be able to direct you to a log or config option (restarting your network services at startup feels a little hackish).
4. On most systems @reboot should also run after a hard shutdown or crash, but there are different cron implementations so YMMV. I've seen comments in different places asserting both.

EDIT (2016/02/17): Removed incorrect blurb on absolute paths; kudos @muru
EDIT (2016/10/17): Added shutdown note
EDIT (2017/09/11): Revised shutdown note. Not really sure on that one.

You can use crontab for this, but if you use sudo, then you will need a NOPASSWD rule in sudoers to do so. (See How to run a cron job using the sudo command.)

It would be simpler to edit /etc/rc.local and add these commands before the exit 0 line.