Internet Connection Sharing with a Windows PC

Gorbachov · 09-25-2003, 11:14 AM

Yes it need a lot of time well spend for reading...But I got used to use the console...

Stoic · 09-25-2003, 12:43 PM

One more thing. I did say you didn't need to specify the DNS servers on the Windows machine. Well, it appears that you actually have to specify them. In Mandrake you can find the DNS server IPs among others via Linuxconf (start as su). Probably there is an easier way to find out...

Gorbachov · 09-25-2003, 01:50 PM

I think I mentioned that!?

Gorbachov

/bin/bash · 09-25-2003, 02:29 PM

Quote:

In Mandrake you can find the DNS server IPs among others via Linuxconf (start as su). Probably there is an easier way to find out...

cat /etc/resolv.conf

Chryzmo · 09-25-2003, 09:06 PM

Hey guys,

It works! Woo!

Thanks a lot for all your help, through the advice from everyone I pieced it together and finally got the Windows PC online.

Thanks again,

Chris

Stoic · 09-26-2003, 02:36 AM

Quote:

Originally posted by /bin/bash
cat /etc/resolv.conf

That looks indeed much easier

Quote:

Originally posted by Chryzmo

Hey guys,

It works! Woo! Thanks a lot for all your help, through the advice from everyone I pieced it together and finally got the Windows PC online.

Thanks again,

Chris

Great to hear! Enjoy the sharing

.

tek8one · 09-26-2003, 07:35 AM

Gorbachov:

Thank you for that code and the insight on what each line does. That was a lot better than reading through the long FAQs and HOWTOs I've found scattered across the internet.

However, I'm a little worried. After executing those commands and setting up rc.local, I noticed something. My external IP address is completely wide open! I have set the Security Level in RedHat to High and only have HTTP and SSH ports open. However, I can access VNC and other services I setup from outsite the network. Im sure there is a way to block unwanted incoming traffic, but I don't know where to begin. Any ideas?

TIA
Tek8one

tek8one · 09-26-2003, 12:10 PM

------

modprobe ipt_MASQUERADE
iptables -F; iptables -t nat -F; iptables -t mangle -F
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -o eth0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward

------

I figured out why all my ports were wide open. the second line in the code that Gorbachov provided, flushes all the tables out (deletes chains), taking away the chains I setup elsewhere. This is fine if you have a cable modem or dsl modem you're connecting to since most come with a built in firewall. For others like myself who have a straight connection to the internet, they need to comment out tha second line to keep your other chains intact and all will be safe and secure. Thanks again Gorbachov. You prevented me from going bald at 22

Tek8one