FC4 IP Masquerading

[Tony Crouch]

Hi Jonathan,
Thanks for your reply with regards to my IP masquerading query. I ran
the two scripts you initially mentioned in your reply. It seems for some
reason (even though the j or jump switches are contained within the
iptables manual, it reports an error ... I have included my terminal
output below.

[root at localhost tony]# /sbin/iptables -D POSTROUTING -t nat -s
192.168.0.0/24 -d  ! 192.168.0.0/24 \ -j MASQUERADE
Bad argument ` -j'
Try `iptables -h' or 'iptables --help' for more information.


[root at localhost tony]# /sbin/iptables -D POSTROUTING -t nat -s
192.168.0.0/24 -d ! 192.168.0.0/24 \ --jump MASQUERADE
Bad argument ` --jump'
Try `iptables -h' or 'iptables --help' for more information.


Any ideas as to why this switch is being reported as being invalid?

Thanks for your help.

Cheers, 
Tony

###################


> 
> Message: 18
> Date: Tue, 25 Oct 2005 19:17:39 +0100
> From: Jonathan Rawle <gmane at jonathanrawle.co.uk>
> Subject: Re: FC4 IP Masquerading
> To: fedora-list at redhat.com
> Message-ID: <djlss3$mtu$1 at sea.gmane.org>
> Content-Type: text/plain; charset=us-ascii
> 
> Tony Crouch wrote:
> 
> > Hi All,
> > I have spent the last few days trying to set up an IP masquerading
> > situation on my home LAN (which only consists of my FC4 notebook and
> my
> > windows XP desktop). I have gone through all the sites and read all
> > about IP tables, but alas I still can't get it setup.
> > 
> > The IPs' of my two machines are:
> > Notebook (aka: masquerading box) : 192.168.0.1
> > Desktop : 192.168.0.2
> > 
> 
> Try the following three lines as a start:
> 
> /sbin/iptables -D POSTROUTING -t nat -s 192.168.0.0/24 -d !
> 192.168.0.0/24 \
> -j MASQUERADE
> 
> /sbin/iptables -t nat -s 192.168.0.0/24 -d ! 192.168.0.0/24 -A
> POSTROUTING \
> -j MASQUERADE
> 
> echo 1 > /proc/sys/net/ipv4/ip_forward
> 
> 
> If it works, to make it permanent, the first two
> (without /sbin/iptables)
> can be added to /etc/sysconfig/iptables. I'm sure there's a proper way
> to
> turn on ip_forward, but I just put the third line in rc.local.
> 
> > My firewall has been turned off within: "Desktop --> System Settings
> -->
> > Security Level".
> > 
> 
> This is not a good idea, even on dial-up. Turn the firewall on, then
> allow
> any traffic through eth0 (or whatever your LAN is on) using:
> 
> /sbin/iptables -I RH-Firewall-1-INPUT 2 -i eth0 -j ACCEPT
> 
> 
> Let us know if it works!
> 
> 
> Jonathan
> 
> -- 
> http://jonathan.rawle.org/
>