I have a new install of Ubuntu 10.04.2 and the network will not connect. This is a dual boot desktop system with Vista. The Vista network is good. When I boot up Ubuntu, the network icon seems to be searching but then the message "Wired network disconnected - you are now offline" appears. I ran ifconfig -a & got:

eth0 Link encap:Ethernet HWaddr 00:1d:09:7b:b5:29
inet6 addr: fe80::21d:9ff:fe7b:b529/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:262 (262.0 B) TX bytes:2520 (2.5 KB)
Memory:fdfc0000-fdfe0000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)

I am behind a wired router with a DHCP Server. Does something need configured to fix the connection?

The output suggests that your IP address doesnt exist...

try running dhclient in a terminal window & see if that brings it up.

Cannot say why you'd have to do that... but...

(That was the 1st time I connected the hard-wire... came right up. )

Also... is the DHCP server setup for inet6?

I don't know if the router supports inet6. It is a linksys BEFSR41 v.2 if that helps. My netbook shows:

inet addr:192.168.1.103 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::8aae:1dff:fe0f:983e/64 Scope:Link
etc.

and the netbook works through the same router with Ubuntu 10.10 so I assume the router does support inet6.

So, when I ran dhclient I got:

steven@steven-desktop:~$ dhclient
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

can't create /var/lib/dhcp3/dhclient.leases: Permission denied
SIOCSIFADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCSIFFLAGS: Permission denied
Open a socket for LPF: Operation not permitted
steven@steven-desktop:~$

You had me confused for a minute... mentioning the netbook...
It looks like there might be some issue with dhclient's permissions...
You shouldnt have to do this.. but you might wanna try
sudo dhclient
to see if root perms will straighten things out...

Cant be of more help as Im still new to Ubuntu myself... hope that helps!

AFAIK dhclient always require root privileges since it is interacting with /dev stuff (more
specifically your nic). The reason why networkmanager/wicd work as regular user is that the nic
management is done by a daemon.

Ok, let's try again. I haven't had time lately to try. I think maybe my router doesn't support inet6 & that is how I am trying to connect. Can someone tell me how to tell Ubuntu to use inet4 instead?

Would Ubuntu 10.10 solve this problem?

I have to keep rebooting into windows to get back to read this forum.