Jul 281998

notes on rebooting and IP numbers

NOTE: It’s amazing how I can look back at articles such as this and realize just how much newbies don’t know. This is a very good example. At some time, you didn’t know the following information either. After some experience, we just take it for granted.

This is a vital point to remember when you are helping others. Don’t assume much.

28 July 1998

The person that helped me out with the name resolution problem also took the time to explain a few points about rebooting.  These comments were based upon my previous "dns" problems.  I’ve included them here because they make for good novice-reading.


There isn’t much need to reboot a Unix box.  Most daemons provide some mechanism for restarting themselves.  For example "kill -hup <process id>".

In theory, you should never have to reboot unless you’ve had a power failure or have installed a new kernel or a major upgrade of the whole system.  Some daemens come with a helper tool.  For example, named, comes with ndc which will send these SIGHUP signals for you.

IP numbers

IP numbers are assigned to network interfaces, not computers.  If a computer has two network cards, each network card will have a different address.  The same computer can be known by more than one IP and be connected to more than one sub-net.

This is a mistake I made.  And it’s been pointed out to me at least three times.