network interface numbers weirdness

[Ali Saidi]

Binary package hint: linux-source-2.6.22

I just installed Gusty with kernel 2.6.22-12.

During the installation two ethernet cards were detected in the machine as eth0 and eth1 (and there are only two). I used eth0 to install the system. Upon rebooting /etc/network/interfaces had eth0 configured as I specified in the installer. However eth0 (and eth1) do not exist. They are both e1000 supported cards and the e1000 driver is loaded. For some reason both eth0 and eth1 are detected as such, however the actual interfaces the kernel sees are eth2 and eth3

grep e1000 /var/log/dmesg
[ 78.371669] e1000: 0000:03:0e.0: e1000_probe: (PCI-X:100MHz:64-bit) 00:0b:db:43:61:b3
[ 78.407129] e1000: eth0: e1000_probe: Intel(R) PRO/1000 Network Connection
[ 78.678746] e1000: 0000:04:0d.0: e1000_probe: (PCI-X:100MHz:64-bit) 00:07:e9:0c:d4:39
[ 78.714164] e1000: eth1: e1000_probe: Intel(R) PRO/1000 Network Connection
[ 87.694177] e1000: eth2: e1000_watchdog: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX

ifconfig
eth2 Link encap:Ethernet HWaddr 00:0B:DB:43:61:B3
          inet addr:141.212.106.76 Bcast:141.212.106.255 Mask:255.255.255.0
          inet6 addr: fe80::20b:dbff:fe43:61b3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:893 errors:0 dropped:0 overruns:0 frame:0
          TX packets:160 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:77550 (75.7 KB) TX bytes:22090 (21.5 KB)
          Base address:0xdcc0 Memory:ff6e0000-ff700000

Note that the hardware addresses that the driver originally noted as eth0 and the device i later configured as eth2 are the same.

[Zed Lopez (launchpad-20-zed2323)]

I had a similar experience. The installer identified the wireless card as eth0 and the wired network interface on the motherboard as eth1. But on rebooting, I had no net access, as they had become eth2 and eth3. Ifconfig made clear what was happening, so a change to /etc/network/interfaces and an /etc/init.d/networking restart made for a quick fix, but this would have stumped a newbie.

It'd be really nice if the installer created /etc/iftab entries for the identified network interfaces' MAC addresses so this didn't come up, though it's probably far too late for Gutsy.

[Launchpad Janitor (janitor)]

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this bug to the new "linux" package. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!