Managing a server's resources

[Belmin Fernandez]

Hello.

I was wondering if anyone could give me tips on managing a server's
resource. Things like:

a) I use my linux server as a rotuer. How can I tell if I'm getting an
unusual amount of traffic from a specific client? Any applications I
should take a look at that might help me? Maybe some built in commands
that chart information like these?

b) I use the 'top' command to see if a program is stuck or something.
Is there a 'smarter' way to do this? 'ps' also does the job but I like
top's ability to sort. Which column should I look at mainly? I look at
the CPU time one (I think that's what it was not near the computer).

c) Any other tips that relate to this subject from you linux pros out
there will be appreciated!!

Thanks for any help you could offer!