port forwarding

[Ed Wilts]

On Sat, Dec 04, 2004 at 11:08:37AM -0800, Gerhard Magnus wrote:
> I have a single-Ethernet port DSL modem hooked up to a router which then
> connects to two boxes running Linux.  I'm not using the DHCP server
> built in to the router -- both boxes have explicitly assigned IP
> addresses, 192.168.1.11 and 192.168.1.12 which appear in /etc/hosts.  I
> want to set up port forwarding to allow ssh from the outside to
> 192.168.1.11 on port 22.  I've set the Fedora firewall "security level"
> to "high" while allowing for the exception of incoming ssh.
> 
> Both the modem and the router have screens for setting port forwarding. 

Then the modem is a lot more than just a modem... 

> My question is: do I have to set one or the other or both?  For example,
> do I need to set the modem to forward port 22 to the router, and then to
> set the router to forward port 22 to the 192.168.1.11?

I'd say so.  My suggestion would be to simply forward all ports from the
"modem" to the router and let it decide where the packets should go from
there. 

> I'm getting very interested in this networking technology and would also
> appreciate any links or references that might be helpful, especially in
> characterizing systems that include machines running different OS's.

What do you mean by "characterizing systems"?  There's really nothing
different about treating a Windows system versus a Linux system - they
have similar networking functionality (with the right add-on software)
and fundamentally do the same thing.

-- 
Ed Wilts, RHCE
Mounds View, MN, USA
mailto:ewilts at ewilts.org
Member #1, Red Hat Community Ambassador Program