Cannot get Realtek r8168 ethernet card up

Question

I've working on Arch Linux and in 99% of time I connect to internet by WLAN but sometimes I need to use ethernet connection, so today I see something strange. My eth0 device is down, and I can't get it up. I tried

# ip link set eth0 up
# ifconfig eth0 up

But after any of above commands ip link shows:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN mode DEFAULT 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DORMANT qlen 1000
    link/ether 8c:a9:82:01:13:6e brd ff:ff:ff:ff:ff:ff
5: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000
    link/ether 14:da:e9:0c:a9:d6 brd ff:ff:ff:ff:ff:ff

Output of lspci -v:

08:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
        Subsystem: ASUSTeK Computer Inc. U6V/U31J laptop
        Flags: bus master, fast devsel, latency 0, IRQ 48
        I/O ports at 8000 [size=256]
        Memory at d3804000 (64-bit, prefetchable) [size=4K]
        Memory at d3800000 (64-bit, prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: r8168

Output of dmesg | grep r8168:

[    7.642820] r8168 Gigabit Ethernet driver 8.032.00-NAPI loaded
[    7.642964] r8168 0000:08:00.0: irq 48 for MSI/MSI-X
[    7.798226] r8168: This product is covered by one or more of the following patents: US5,307,459, US5,434,872, US5,732,094, US6,570,884, US6,115,776, and US6,327,625.
[    7.798232] r8168  Copyright (C) 2012  Realtek NIC software team <nicfae@realtek.com> 
[   19.263312] r8168: eth0: link down
[  404.826781] r8168 Gigabit Ethernet driver 8.032.00-NAPI loaded
[  404.827275] r8168 0000:08:00.0: irq 48 for MSI/MSI-X
[  404.981486] r8168: This product is covered by one or more of the following patents: US5,307,459, US5,434,872, US5,732,094, US6,570,884, US6,115,776, and US6,327,625.
[  404.981491] r8168  Copyright (C) 2012  Realtek NIC software team <nicfae@realtek.com> 
[  405.011797] r8168: eth0: link down

Output of dmesg | grep eth0:

[    7.798230] eth0: Identified chip type is 'RTL8168E/8111E'.
[   19.263312] r8168: eth0: link down
[   19.263709] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[  404.981490] eth0: Identified chip type is 'RTL8168E/8111E'.
[  405.011797] r8168: eth0: link down
[  405.012293] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready

Answer 1

Seems RealTek 8168B has problems on Debian Squeeze. Try those:

• If you have problems with the network interface not going up with RealTek 8168, this may help and provide insight (ie. realtek firmware problem): http://serverfault.com/questions/384165/after-installing-debian-squeeze-ethernet-does-not-come-up

• If you have problems with the kernel not even loading the correct module = drivers for RealTek 8168, this may provide necessary insight (ie. hardware detection problem): http://djlab.com/2010/10/fixing-rtl8111-8168b-driver-debian-ubuntu/

Answer 2

I've had some similar issues on that same adaptor for unidentified causes. The only solution was to power down the machine, just rebooting, unloading module or various "reset"s via /sys interface didn't fix it.

Installing the driver downloaded from RealTek as opposed to the one included in the vanilla kernel seems to cause the issue to occur less often.