>>>> My laptop's >>>> r8169 eth0 appears under ifconfig even when there's no ethernet cable >>>> attached. That's the expected behavior isn't it? >>> >>> Sure; ifconfig will even tell you if the link is up or down. Just >>> because the link is down doesn't mean the interface isn't there. :) >> >> I see eth0 under ifconfig on my laptop but not on my desktop. >> Strangely, on my desktop eth0 does appear under iwconfig (no wireless >> extensions). dmesg pertaining to eth0 and r8169 looks normal. lspci >> -v says: >> >> Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI >> Express Gigabit Ethernet controller >> ... >> Kernel driver in use: r8169 >> >> But no eth0 under ifconfig. > > Time to go for a walk in /sys, to find out more information. > > Check out /sys/bus/pci/devices > > Now, with lspci, a NIC will look something like this: > 01:08.0 Ethernet controller: Realtek Semiconductor Co., Ltd. > RTL-8139/8139C/8139C+ (rev 10) > > If I look under /sys/bus/pci/devices, I'll see a corresponding > directory (compare the first column from the lspci output): > 0000:01:08.0
I have: # lspci ... 04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06) # ls /sys/bus/pci/devices 0000:00:00.0 0000:00:0a.0 0000:00:13.0 0000:00:14.3 0000:00:15.1 0000:00:18.1 0000:01:05.0 0000:04:00.0 0000:00:01.0 0000:00:11.0 0000:00:13.2 0000:00:14.4 0000:00:16.0 0000:00:18.2 0000:01:05.1 0000:00:04.0 0000:00:12.0 0000:00:14.0 0000:00:14.5 0000:00:16.2 0000:00:18.3 0000:02:00.0 0000:00:09.0 0000:00:12.2 0000:00:14.1 0000:00:15.0 0000:00:18.0 0000:00:18.4 0000:03:00.0 # ls /sys/bus/pci/devices/0000:04:00.0 broken_parity_status device irq msi_bus reset resource2_wc subsystem_device vpd class dma_mask_bits local_cpulist net resource resource4 subsystem_vendor config driver local_cpus remove resource0 resource4_wc uevent consistent_dma_mask_bits enable modalias rescan resource2 subsystem vendor So I guess I'm missing net:eth0 in that last one? It's a nearly brand new motherboard: http://www.newegg.com/Product/Product.aspx?Item=N82E16813128490 Maybe the r8169 driver hasn't caught up? - Grant > If I run 'ls' in that directory, I see: > > -rw-r--r-- 1 root root 4096 2011-08-01 15:19 broken_parity_status > lrwxrwxrwx 1 root root 0 2011-08-01 15:19 bus -> ../../../../bus/pci > -r--r--r-- 1 root root 4096 2011-08-01 15:11 class > -rw-r--r-- 1 root root 256 2011-08-01 15:11 config > -r--r--r-- 1 root root 4096 2011-08-01 15:11 device > lrwxrwxrwx 1 root root 0 2011-08-01 15:11 driver -> > ../../../../bus/pci/drivers/8139too > -rw------- 1 root root 4096 2011-08-01 15:19 enable > -r--r--r-- 1 root root 4096 2011-08-01 15:11 irq > -r--r--r-- 1 root root 4096 2011-08-01 15:19 local_cpus > -r--r--r-- 1 root root 4096 2011-08-01 15:19 modalias > -rw-r--r-- 1 root root 4096 2011-08-01 15:19 msi_bus > lrwxrwxrwx 1 root root 0 2011-08-01 15:19 net:eth2 -> > ../../../../class/net/eth2 > drwxr-xr-x 2 root root 0 2011-05-12 10:47 power > -r--r--r-- 1 root root 4096 2011-08-01 15:11 resource > -rw------- 1 root root 256 2011-08-01 15:19 resource0 > -rw------- 1 root root 256 2011-08-01 15:19 resource1 > lrwxrwxrwx 1 root root 0 2011-08-01 15:19 subsystem -> ../../../../bus/pci > -r--r--r-- 1 root root 4096 2011-08-01 15:19 subsystem_device > -r--r--r-- 1 root root 4096 2011-08-01 15:19 subsystem_vendor > -rw-r--r-- 1 root root 4096 2011-08-01 15:19 uevent > -r--r--r-- 1 root root 4096 2011-08-01 15:11 vendor > > > So, you an see a file named 'net:eth2', so I expect it would show up > as eth2, absent any udev renaming or aliasing rules. > > -- > :wq