ADSL connection configuration - router/nat configuration

ADSL connection configuration - router/nat configuration

Post by Gille » Mon, 08 Jan 2001 20:18:49

I am relatively new to linux, so any help/guidance would be really
I am ok with shell commands and so, but not familiar enough with network
Unfortunately, I didn't find all the answers in the howtos (some require a
good practice of the system).

Currently I have a private network setup with a win2k router setup as a nat
(with 2 nic cards : one to the modem / one to the hub).
The win2k router is also the dhcp server (netmask and a dns
relay for external queries.
The router has a static address and gets a dynamic address on
the demand dial interface when connected to the isp.
It gets also the dns addresses from the isp. The adsl connection to the isp
is via pppoe.

I have an old laptop that is now running rh7 on the network via eth0 (xircom
pcmcia adapter), configured to get its address via dhcp.
The kernel (rh7 default workstation configuration) seems to be configured
for masquerading and all that stuff ...

now ...

I want to setup this laptop to be the router / nat.

I would like to do the migration in 3 steps:
    - first connect the laptop interface directly to the modem and configure
it to dial into my isp and get the connection up
    - connect the modem to the hub and connect my laptop to the hub ( have
the laptop be the router with two ip addressed on the same ethernet
interface )
    - then configure it for router / nat / firewalling


for the first step:

I first need to reconfigure the eth0 interface to have a static address
( on the private network.
What are the changes in the ifcfg-eth0 configuration file ?
I just changed the ipaddress, netmask ... and removed dhcp, but I can't get
ifconfig to get the interface up and configured.
Then to prepare for step 2, I would like to setup two addresses on the same
ethernet interface.
How can I do that ? I tried splitting ifcfg-eth0 in ifcfg-eth0:0
( and ifcfg-eth0:1 (
But there too I can't get it to be up and configured correctly with

thanks for help on this.

I have pppd and pppoe installed (and I guess pppoe configuration files setup
What do I have to do to connect to the isp manually ? I cannot use minicom
(it's no a serial connection).
While we are on it, what do I have to do then to have the connection setup

... I will see after for the next steps ...

thanks, Gilles