[TriLUG] Iptables help

[Jon Carnes]

On Wed, 2004-03-24 at 08:59, Greg Kuhn wrote:
> Hello all, 
>       I have what is probably a simple question, I just don't have the answer. Here is the situation, I am currently enrolled in wake techs high performance computing program, and this semester I am taking their linux security class among others. The instructor wants as the last part of our current lab to do the following:
> 
> from machine 1 ping machine 2 and have the ping forward to machine 3, so it looks like the ping is actually coming from machine 2.
> 
> I set up machine three to log the activity, when i ping machine 3 directly from 1 or 2 it logs it, but my forwarding/masqing rules don't seem to be working, when I try to ping 3 thru 2 from 1.
> 
> I tried using the rules from  my server at home but something is missing.
> 
> So if you could please send the iptable rules needed to accomplish this task.
> 
> Thanks, Greg

You should post what you already have (disguising what you feel you need
to)... and in this case, we'll probably show you "how to fish", rather
than give you the fish:
   http://www.linuxquestions.org/questions/archive/3/2003/08/2/80009

Good Luck.

BTW: I like to use Xinetd to do forwarding of specific services.  Works
fine and you can still log it using IPTables (or xinetd). Makes it very
easy to redirect, turn off, turn on, etc.  As with everything in
Unix/Linux you can do it any number of clever ways.