dhcp will not configure eth0

[garrone]

Hi,
 I have a sony vaio VGN-NR37G laptop on which I have recently installed
 ubuntu-intrepid, from ubuntu-8.10-desktop-i386.iso.
 
 I cannot get eth0 working from an ethernet cable modem. I can plug the cable into a
 desktop (AMD64) running intrepid and it always reconnects no problems. However
 the same cable in hopefully a similar distribution fails to fire up the
 networking.

 Using tcpdump, incoming dhcp packets can be observed with the
 prospective address. The utility dhclient triggers the install scripts,
 and avahi will even assign the address to the eth0 port, if the command
 "dhclient -1 eth0" is run. However dhclient always ultimately 
 reports a failure, (no DHCPOFFERS received), and exits. DNS never
 works, even when occasionally an address is assigned to the port by
 avahi.

 I must say I do not really understand the interaction between dhcp,
 avahi, and network-manager. They are all involved in the chain of
 events. I imagine that dhcp has control and is ultimately failing, so I
 should focus my debugging there. I have compared "/etc" configurations with
 the working desktop, and cannot see anything significant.

 I am looking for any debugging suggestions, or possibly packages 
 that should be updated to address this problem (Without networking, each package has to be 
 downloaded separately and copied and updated with dpkg).
 Cheers,
  Peter