DHCP and routing

[Rodolfo J. Paiz]

At 09:50 1/11/2004, you wrote:
>hello i was wondering if any one could help me, i have a single fedora
>box with two network cards
>eth0 - connected to my isp wich DHCP's all my IP information and DNS
>information this works fine......
>and
>eth1 - Connected to my Hub and routes the isp to my other machines
>including virius other network services like nfs and samba...

I think I understand that you've got this all done OK... but I'm not sure. 
So just to be sure: does all of this actually work already?

If not, allow me to suggest that you spend a little time (maybe an hour or 
so) reading the documentation for Shorewall (www.shorewall.net) and then 
installing it. It is a great firewall software that will allow you to do 
all that very easily. Especially see the "two-interface" quick-start guides 
and examples.

>first of all i have given my eth1 a fixed ip of 192.168.0.1 and im
>trying to run dhcp service it did nothing so i played with dhcpd.conf
>file and it dosent work at all now it has the error: Line 1 : semicolon
>expected.

Post your dhcpd.conf here. But first keep in mind:

         1. All lines in dhcpd.conf end with a semi-colon. Only exception: 
lines that end in or only contain closing braces ("}").

         2. Edit /etc/sysconfig/dhcp, which contains the line "DHCPARGS=". 
Change that to "DHCPARGS=eth1" so that it only serves your internal network 
and doesn't try to serve DHCP to your ISP.

>and i just havent got a clue about routing im gussing i have to route my
>isp ip to 192.168.0.0 but the porblem is that its a dhcp ip and will
>change and i cant be botherd to change it every 5 seconds.

What you want is called masquerading. The best suggestion I can give you is 
to read the IP Masquerading HOWTO at www.tldp.org, then install Shorewall 
instead of doing everything by hand.

Cheers,


-- 
Rodolfo J. Paiz
rpaiz at simpaticus.com
http://www.simpaticus.com