CentOS - Jul 2007 - Newbie ADSL configuration, ppp0 can't activate & config not found

I am frustrated. This is a dual boot box, Win XP (Spanish) and CentOS 4.4.
The phone company man came today and installed ADSL to the WinXP side and
that works fine. I can't get the box online, while in CentOS 4.4. The ADSL
router has a fixed IP address (192.168.1.1) and he configured it to get
the IP from the ISP via DHCP and get the DNS servers automatically. When I
try that on CentOS (which is what I use 99% of the time), it doesn't
connect. In the Network Configuration for eth0, things seem OK, but the
configuration for xDSL, ppp0, probably needs something I do not have in it
and it won't activate. Questions: (a) should I have network configurations
for both eth0 and ppp0? I've tried it with both and only with ppp0. (b) is
there a possibility that the NIC, which is integrated onto the motherboard
and has always worked fine on our home LAN, as eth0, won't work properly
as ppp0? If so, should I disable it and install a NIC in the box? I've
looked in the RHEL Step by Step Guide for RHEL 4 and Systems
Administrators Guides, but they don't seem to cover this issue. Any links
to a step by step how to, to do something I believe is simple, but, where
I'm missing something, will be greatly appreciated! TIA, Lanny

mailing-lists at computer2.com wrote:
> I am frustrated. This is a dual boot box, Win XP (Spanish) and CentOS 4.4.
> The phone company man came today and installed ADSL to the WinXP side and
> that works fine. I can't get the box online, while in CentOS 4.4. The
ADSL
> router has a fixed IP address (192.168.1.1) and he configured it to get
> the IP from the ISP via DHCP and get the DNS servers automatically. When I
> try that on CentOS (which is what I use 99% of the time), it doesn't
> connect. In the Network Configuration for eth0, things seem OK, but the
> configuration for xDSL, ppp0, probably needs something I do not have in it
> and it won't activate.
If you have a router, then the ADSL connection you have is handled by 
the router, and is invisible to you, on the LAN side of the router. The 
router could be connecting to the WAN via a piece of wet string, as far 
as you care. So you should just have eth0 do DHCP and leave it connected 
to the router. You'll get an address like 192.168.1.2 from the router. 
You don't need ppp0 at all; to Centos the router appears like a LAN that 
routes to the Internet.

In Windows, do "ipconfig" in a Command window, and you'll see what
I
mean. You should see something similar with ifconfig in Centos.