Re: FreeBSD 4.2 ipfw natd -- Port Forwarding?

[Russ <xminer () home com>]

At 02:23 AM 12/21/2000 -0500, you wrote:
> Hi,
>         What your looking to do can be done with NAT.  I did something 
> similar in the following manner:
>
> 1.) I created a file called natd.conf and placed it in /etc with the 
> following lines:
>
> redirect_port tcp 192.168.1.3:8877 8877
> redirect_port upd 192.168.1.3:8877 8877
>
> 2.) Then I did a chmod +x /etc/natd.conf
>
> 3.) Then, I added the following line in the /etc/rc.conf 
> file.   natd_flags="-f /etc/natd.conf"
>
> 4.) Reboot, it should work fine.  If you cant reboot, you can do this from 
> the commandline:  /sbin/natd -f /etc/natd.conf -n xl1 (replace x1l with 
> your public ethernet card)
>
> 5.) Then, you will just need to punch a hole in your firewall to allow 
> traffic to flow to those ports.




I will give the natd.conf a try but I think this is my question, how do I 
write the rule to allow these port to be open in my rc.firewall (ipfw) ? I 
can't seam to get the syntax right...  then the natd.conf entry you suggest 
should work.

$fwcmd allow from any to any 8877

or do I need to specify   $fwcmd allow  tcp  8877 from eif  (external 
interface)

I want the firewall to allow incoming traffic on that port  so natd can 
then redirect them... right?

Thanks





>         Hope this helps,
>
> -Willy
>
>
> At 01:19 12/19/00 -0800, you wrote:
> > Hi, fist time poster, thanks for the cool mailing list...
> >
> > I am using FreeBSD 4.2 and have set up a pretty good firewall using ipfw 
> > and natd via some tutorials and documentation I have found. So it works 
> > but now I need to customize it a little...
> >
> > Question:  How can I allow incoming connections through my firewall.  The 
> > client lets me specify what port to listen to incoming requests on, 
> > before I was using a router that had built in port forwarding... So the 
> > client is set to listen on 8877 and router forwards incoming request to 
> > port 8877 to computer with ip 192.168.1.3 for port 8877, you get the picture?
> >
> > I would like to learn how to write the rule in my ipfw script that might 
> > do the same thing, forward incoming requests to my external ip on port 
> > xxxx to internal ip xxx.xxx.xxx.xxx port xxxx.  The port would not change 
> > of course...
> >
> > how do I write the rule? I suppose this rule could be used for any 
> > incoming request, and I am sure people use it to allow access to http and 
> > ftp through a firewall, so there must be an acceptable rule to do it, any 
> > ideas?
> >
> > $ipfw pass tcp "for port 8877 only" to 192.168.1.3:8877 via $oif 
> > (external interface) ?  I have no clue how it should be.
> >
> >
> > _______________________________________________
> > firewall-wizards mailing list
> > firewall-wizards () nfr com
> > http://www.nfr.com/mailman/listinfo/firewall-wizards


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