I'm not new to Linux, but this is the first time I have attempted to set up a Linux server. For some reason I cannot connect to the internet from within the network.

I have only two computers:

A) Red Hat 7.3 -- an old computer I am trying to set up as an apache/network server/router.

B) Red Hat 8.0/Windows XP -- this is my main computer, normally it is just connected directly to my cable modem.

How I have them set up:

Computer A has two ethernet cards....eth0 is connected to my cable modem, and is configured to use dhcp...eth1 is connected to my hub and has the ip addr 192.168.0.1, netmask 255.255.255.0. Also, I have enabled ip forwarding in /etc/sysctl.conf.

Computer B has one ethernet card...eht1 is connected also connected to the hub and has ip addr 192.168.0.2, netmask 255.255.255.0, gateway 192.168.0.1, nameserver(s) I got from my isp. I have been able to set it up this way in both windows and linux.

After disabling the firewall on the server, I have been able to ping and ssh between both computers....but I cannot access the internet from computer A. From everything I've read, my setup should be okay, but I cannot figure out why it's not working properly.

To anyone who can help me with this, I will be eternally thankfull.....

Thank you!

Oops...

I forgot to mention that the server connects to the internet just fine....I thougt I might have to clone the mac address from my normal computer, but this didn't matter, as my isp just assigned a new ip address when I conneted the server to my modem.

Thanks.

never done this myself, but i recall you need support for routing compiled into your kernel

just thought could be somewhat useful

Have you tried:

iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -j MASQUERADE

to setup iptables for Masquerading?

Thank you so much for your help!

I had a feeling there it had something to do with my iptables...but I didn't know how to set it up to masquerade....works perfectly....

Thank you!

You're Welcome, you may want to look into some blocking rules, so you are not wide open to the internet.

something like

iptables -I INPUT -s 192.168.0.0/24 -j ACCEPT
iptables -P INPUT DROP

should get you started.

Thanks again.....I would ask you what these rules do, but maybe it's better if I just read up on them myself...in fact, I think I'll do that right now...

Thanks

To get you started, the first rule allows all traffic from the

192.168.0.0/24 range(192.168.0.1-255)

the second rule denys all traffic from everywhere else.

Both act on the input chain which in turn will inspect every packet the machine gets(with the exception of those dropped on prerouting). It would be in your best interest to choose an IP that's not in the 192.168.0.0/24 range tho, and instead chose something more like 192.168.5-240.0/24 range, .0.X is an overused and overspoofed IP.