Networking

[prata at kuei-jin.org]

On Wed, Mar 10, 2004 at 04:34:38PM +0000, Gordy wrote:
> HI all,
> 
> I want to network my daughters computer which is running XP as she gets
> a little fed up when I boot into Fedora from XP that she can't connect
> to the net.. 
> 
> My problem is that I am on cable which uses my ethernet on my
> motherboard. The modem is connected through the usb ports but wont work
> unless I have my on board network card turned on...
> 
> How do I get my daughter connected to my Fedora box?
> If it means buying another network card which make of PCI card do you
> recommend to run with Fedora?
> 
> I am new to all this so sorry if it may seem a stupid question..
> 
> Thanks in Advance,
> 
> Gordy
> 
> 

You would need to buy another ethernet card. I use cards that function on the tulip module. I have several d-link cards that work just fine. Typically, just about any pci ethernet card should work. You can check Red Hat's Linux compatibility page if you want to be absolutely sure you buy somethin' that will work for you.

You will need to set your linux machine up so that IPTables forwards packets out from your network to the net. You will also want to make sure you have the kernel options in /proc/sys/net/ipv4/ set to 1 for ipforwarding and the ip dynamic address hack. You can do so with the following commands in a terminal, there is also the /etc/sysctl.conf file to set it up but I forget the syntax as of this moment.

echo "1" > /proc/sys/net/ipv4/ip_forward
echo "1" > /proc/sys/net/ipv4/ip_dynaddr

The above commands can be put into /etc/rc.local so that at boot your forwarding is setup for the kernel. IPTables requires a simple forwarding policy that looks something like the following for me at least on ADSL. It goes in the *filter section of /etc/sysconfig/iptables.

-A FORWARD -i ppp0 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT
-A FORWARD -i eth1 -o ppp0  -j ACCEPT
-A FORWARD -i ppp0 -j REJECT

And you'll need these lines added to the end of the iptables file.

*nat
-A POSTROUTING -o ppp0 -s 192.168.1.0/24 -j MASQUERADE
COMMIT

The above rule is assuming your outgoing interface (the internet connection itself) is ppp0. For you it may or may not be this. It may simply be eth0 for you.

Also, my forwarding rules may not work out of the box for you, because again, your actual internet connection may not be ppp0. It's likely eth0 or somethin' similar. If you have questions please let us know.

HTH,

Alex White