Update Jan 2013: this driver issue was fixed in Ubuntu 12.04 / kernel 3.2.0-14 or so.
Ubuntu doesn’t work out of the box with my ethernet adapter. The ethernet interface is very slow to come up after boot, taking 10-120 seconds. The problem is the Realtek 8111 or 8168, a very common motherboard ethernet adapter. The motherboard docs say it’s a Realtek 81111E. The Linux drivers are broken. Apparently this is a common problem across many Linux variants and people report other problems, too, packet loss and dropped packets. It’s a four year old bug in Ubuntu! How to fix it? (Other than buying a new NIC; Realtek NICs are not well loved.)
I did a lot of research. One proposed fix is to get a different device driver, from Realtek, not the Linux kernel sources. (More notes). Another suggestion is to enable Wake-on-LAN (via Windows), but I don’t really believe that will work. A third option is to upgrade kernels, there’s some possibility that the mainline Linux driver is better. (Most recent Ubuntu bug is 864196).
I decided to try Realtek’s driver. r8168-8.027.00. md5sum:
Sadly, it doesn’t fix my problem. The NIC still takes 10-200 seconds to come up after boot. I also tried enabling wake-on-lan (via Linux, ethtool) and that didn’t fix it either. No surprise but I thought I’d give it a shot. I’m left with the conclusion there is no fix for this bug right now, despite the superstitions about Wake-on-LAN, or r8168 drivers, or whatever.
BTW, the autorun.sh script that comes with the r8168 driver from Realtek is pure evil. First, it unloads your ethernet driver. Completely killing your machine if you’re logged in via ssh and don’t have physical access! Then it goes and rewrites a bunch of stuff in /lib/modules and rebuilds your initram disk. It seems to get this right, but it’s awfully intrusive. I finally removed r8168.ko by hand and did an “apt-get install –reinstall linux-image-3.0.0-15-server” to set things back.
I’m going to try living with this bug; I never reboot the box anyway. The first time I experience massive packet loss, or the ethernet doesn’t come up after boot, I’m getting a real NIC and putting it in a PCI slot. And never again buying a motherboard with a Realtek NIC for Linux use.
Details from lspci -v from stock Ubuntu, before I tried adding the r8168 driver:
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06) Subsystem: ASUSTeK Computer Inc. P8P67 and other motherboards Flags: bus master, fast devsel, latency 0, IRQ 45 I/O ports at e000 [size=256] Memory at d0004000 (64-bit, prefetchable) [size=4K] Memory at d0000000 (64-bit, prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: r8169 Kernel modules: r8169