USB network to dsl

I have problems setting up my computer to connect to internet using the adsl
usb modem.

This is what I have tried so far, I am new to Linux so I may have missed
simple things, I am using Redhad Enterprise 3 on an IBM thinkpad r40.

in /etc/modules.conf I have a line like this:
alias eth1 CDCEther (it have been autogenerated by some program, probably
redhat-config-network or possibly kudzu, but I guess it should be there.

There is also a file ifcfg-eth1 (also auto generated by the same program i
figure) containing:
PEERDNS=yes
TYPE=Ethernet
DEVICE=eth1
BOOTPROTO=dhcp

And I can see the device in redhat-config-network (Network device controll)

I have also tried running:
modprobe CDCEther
modprobe usbnet

Both seem to work fine (they doesnt say anything that is)

When I run
ifconfig -a they doesn't show up

And when I try:
ifdown eth1

I get
SIOCGIFFLAGS: No such device

And when I run
ifup eth1

I get
CDCEther device eth1 does not seem to be present, delaying initialization.

All commands and files seem to work as they should so I guess I have missed
a step or two somewhere. Any pointers will be looked at carefully.

Tim