router using FC4

[LC]

----- Original Message ----- 
From: "Tim" <ignored_mailbox at yahoo.com.au>
To: "For users of Fedora Core releases" <fedora-list at redhat.com>
Sent: Wednesday, May 24, 2006 12:25 AM
Subject: Re: router using FC4


> On Tue, 2006-05-23 at 23:59 +0800, LC wrote:
>> I am trying to make a router using a FC4. I have 2 NICs in the machine.
>> Install FC4 using minimium. Eth0 is set to DHCP, connected to an ethernet
>> modem and ETH1 has IP 192.168.1.1, netmask 255.255.255.0 connected to a
>> switch. Installation was a success and rebooted the box. Clients machines
>> are unable to ping 192.168.1.1. But when i unplug the modem and reboot,
>> clients are ablt to ping 192.168.1.1. I realised if the box booted up 
>> both
>> ETH0 and ETH1, clients are able to ping 192.168.1.1. But if i ifdown ETH0
>> and ifup ETH0, clients are able to get reply from 192.168.1.1.
>
> What's the other interface's address?  If they're both 192.168.1.x with
> a 255.255.255.0 netmask you're going to strike problems, you've got two
> subnets, they need to be addressed accordingly.
>
> e.g. eth0 192.168.0.1/255.255.255.0
>     eth1 192.168.1.1/255.255.255.0 using 192.168.1.x (above) as its 
> gateway
>     and clients should use the 192.168.1.1 as their gateway

The modem assigned eth0 to 192.168.1.2. If i manually change the IP of eth0, 
the modem refused to dial