Topic: TCPIP Port Forwarding

[David Campbell]

I know that the linux kernel allows port forwarding over a network - that is, when someone in the outside world accesses a certain port on the gateway, lets say..  port 40000 of IP xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx:40000) it will route all packets sent to that address to a machine in the network on a certain internal IP and port.  (192.168.0.x:21)

Know what I mean?  I'm wondering if anyone has figured out how to get this done with e-smith.  I'm looking to use this wonderfull product as the base for my home network, but I need a solution that is capable of port forwarding.

Thanks,

Dave.

[Orville Carter]

David,

Try the "search" link for port forwarding. Lots of answers are in the archieve.
See the comment following. ALL CREDIT TO THE ORIGINAL AUTHOR:b1tch-x.

Orville

>Author: b1tch-x
 > Date:   07-16-2000 00:48

>  There is a small packet forwarding program called "redir" It can listen on a set port and forward all the
>  packets to the specified IP and port of another machine. It can also do transparent proxing so that the
>  originating computers IP shows up at your internal machine instead of the forwarding machine. It also has is
>  compatible with ftp servers.

>  http://freshmeat.net/appindex/1999/03/14/921462694.html

>  There is an RPM version for installation.
>  usage:
>  redir --lport= --cport= [options]
 > redir --inetd --cport=

>  Options are:-
>  --lport= port to listen on
>  --laddr=IP address of interface to listen on
>  --cport= port to connect to
>  --caddr= remote host to connect to
>  --inetd run from inetd
>  --debug output debugging info
>  --timeout= set timeout to n seconds
>  --syslog= log messages to syslog
>  --name= tag syslog messages with 'str'
>  --bind_addr=IP bind() outgoing IP to given addr
>  --ftp redirect passive ftp connections
>  --transproxy run in linux's transparent proxy mode

>  Version 2.0 - $Id$

[cary]

Do a search, hell get "rpmfind" (by far the greatest time saver for any rpm packaged linux suite) and do a rpmfind ipmasqadm.  This allows for port forwarding.  the syntax is quite easy and if i remember correctly ( my linux box is down as I test ou one of these linksys hardware internet routers ) is as follows

/usr/sbin/ipmasqadm portfw -L ip port -R "internal ip" port

you can also do ranges with autofw but i have heard this breaks down after running ot for some time, something about not syncing the resources with the kernel or something.

/usr/sbin/ipmasqadm autofw -L ip port:ports -R "internal ip" port:ports

I use just a small do until script with portfw on mine which I am not even going to try and remember at 5am