[K12OSN] OT:ipchains, firewalls, nat, forwarding

Henry Burroughs hburroughs at HHPREP.ORG
Tue Dec 6 18:09:49 UTC 2005

I use a program called FireHol (firehol.sf.net), which uses a simple
configuration file to write iptables codes.  It works from shutting all
the holes and then poking certain things through. I have a pretty decent
set of definitions which do some port forwarding and redirection and it
works nicely.

Henry Burroughs

On Sat, 2005-12-03 at 16:09 -0500, Mike Heins wrote:
> Quoting Eric Brown (ericbrown at mi-spot.com):
> > I call this OT because it's not on a K12LTSP installation.  I chose not to
> > install a firewall on my K12LTSP installation to simplify matters, since our
> > district is  "supposed" to handle all that.  I never had any trouble with
> > the terminal server forwarding things.
> > 
> > I just recieved another server where the vendor installed Fedora core 4 with
> > the  "Install everything" option, as well as installing a firewall.  THis
> > machine is going to act as a gateway machine and a file server for a bunch
> > of XP machines.  Thanks to a question I asked this group a few months ago, I
> > managed to get DHCP running.  With some googleing, I can ping an external IP
> > from one of the XP machines.  I would like to allow dns and web access, but
> > I want to kill any MSN access and pretty much anything else.
> > 
> > So I'm split.  I could ease my headach and turn off the firewall.  Would the
> > fileserver then allow all traffic through it?
> Yes. But typically, the simple Linux firewall setup only blocks incoming
> connections. the settings will allow most *outgoing* traffic.
> > 
> > OR (and I've been searching on this all day), how can I turn it on to allow
> > port s 53 and 80 through the file server.  Better yet, can anyone point me
> > to a very *simple* explanation of how to do this in general (give a man a
> > fish...).  All references I could find were too lengthy or strictly involved
> > ppp which isn't being used here.
> > 
> You could use iptables to limit outgoing traffic as well, but it is
> hard.
> I am a big command-line guy, but firewalls are too complicated and too
> detail-oriented to deal with on that basis. So I recommend using a tool
> like GuardDog to manage your firewall.

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