[lug] Multiple Questions

[Pedersen, Michael J]

I'll toss in my answers to these one at a time :)
> 1.) Any advice on the setup and use of qmail will be appreciated. (I
> heard it was better than sendmail.)

Can't help there, unfortunately. Never used qmail.

> 2.) I'm going to be reloading linux on a main server. Is 
> there a way to
> keep all of the user accounts and passwords?

Yes.  The following files need to be saved (at minimum, there may be a few
others I'm missing):

/etc/passwd
/etc/groups
/etc/shadow (this one has to be backed up only if shadows passwords are
turned on)
/home/*

> 3.) Has anyone had experience with port sentries? Could you share
> information with me?

Sorry, never used them.

> 4.) Is there anything special I have to do in order to 
> disable ports? I
> don't want some services running on some computers and I don't want
> access through the ports.

/etc/inetd.conf is a good place to kill most services.  However, some don't
get started by inetd (sshd and samba come to mind).  For these, you have
three options: Remove the package (if it ain't installed, it can't start).
Never install the package. Or keep the service from starting.  Depending on
your distribution, the commands to do so will be different.

> 5.) Any tips/info on configuring NFS would be great.

If at all possible, don't.  It's considered one of the biggest security
holes you can have. If you MUST install it, configure a firewall, and put
the NFS machines behind it, and review every security alert you can find on
it to lock it down.  Outside of that, there's a lot to it, but you can find
some pretty good info by reviewing 'man exports'.

Sending it to the list, so other folks can correct me as needed :)