Presumably you will be using one ethernet for connecting to a modem, (or
router?) and the other to connect to another computer. This should be
OK, but it might be best to start with just one, connected to the modem.
You didn't say what further explaination you required, but here are the
settings and procedure that worked for me.
Click on System/Administration/Networking. Enter password. Click on
Ethernet connection eth0 or eth1 as required. Click on properties.
Chose Static Config.
Enter the IP address you want to use for your computer. I used
192.168.1.10
If you then click on sub-net mask, it will come up 255.255.255.0 which is OK
Then set up the gateway address. This is very important as it carries
all the internet traffic to you, and also allows you to communicate with
your modem. The address should be stated in your modem handbook, it's
usually 192.168.0.1 or 192.168.1.1
When you've done all this Click on OK, and then select the General
settings. In Hostname, enter the name you give to your computer, I use
linux-02 for this machine. Leave Domain Name blank. Click OK
Next select DNS. Enter the IP address for the DNS servers. You should
get this address from your ISP. All ISPs will have different adresses,
and you may get more than one, I got two. This address is very
important as the remote server converts an http:// string, such as
www.yahoo.com, to a numerical IP address.
Click Add. Click on the highlighted band, and enter the IP address,
then IIRC, press return. Repeat if you have another address to enter.
This particular interface isn't very user friendly, but IIRC it's
important to press return after entering each address.
Leave the search domains blank. Click on OK.
Finally, go back to the connections tab, and deactivate the interface.
In v6.xx the is a deactivate button, in 7.04 there is a small box just
before the description of each interface. Click OK, and exit from the
network menu.
Re enter the network menu and activate the interface, finally click OK.
You should now be able to ping the modem, and the DNS server(s). If you
get a response, then your browser should be able to access the internet.
Hope this helps. If it doesn't let us have some more details.