Hi,
Since yesterday, i'm having a strange problem with my eth0 card. it does not come UP:
In logs (messages) i see this message:
ADDRCONF(NETDEV_UP): eth0: link is not ready

ETHTOOL shows this:
Settings for eth0:
Supported ports: [ MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Speed: 10Mb/s
Duplex: Half
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: g
Wake-on: g
Current message level: 0x000000ff (255)
drv probe link timer ifdown ifup rx_err tx_err
Link detected: no

Why no link is detected anymore, the cable is plugged, is good, i have checked with mode than one good cable.

cosmin@Dell:~$ lspci | grep Eth
03:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02)


cosmin@Dell:~$ lshw -C Network
*-network
description: Ethernet interface
product: BCM4401-B0 100Base-TX
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth0
version: 02
serial: 00:1c:23:b4:dd:68
size: 10Mbit/s
capacity: 100Mbit/s
width: 32 bits
clock: 33MHz
capabilities: bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=b44 driverversion=2.0 duplex=half ip=192.168.53.151 latency=64 multicast=yes port=twisted pair speed=10Mbit/s
resources: irq:17 memory:f9bfe000-f9bfffff


I searched almost a full day on google to see how other peapole solved this issue, many of them use ifdown and ifup, but for me it is not working, no link is detected. In my mind, i think that the eth card is "broken".

Can some one help me find a solution or be absolutelly sure if the card is "broken" or not?
Do you think it helps to reinstall the system? I have Ubuntu 11.04.

lshw and lspci just say about the ethernet drivers. Can you try connecting the same Ethernet cable with another system to see if that works? Or can you try connecting this system another ethernet cable? This may be initial steps to identify the issue. And after inserting the cable, is Ethernet card LED is blinking?

The cable was just fine. I turns out that the RJ45 connector did not made a good contact anymore, that is why no link was detected.
The quick solution, and i think the only one was to change the mainboard with another one. and now is working.