NetworkManager does not detect ethernet connected

[Sean Davis]

NetworkManager detects when an ethernet connection is lost, but is anable to restore a connection when the cable is reconnected.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: network-manager 0.9.8.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-11.20-generic 3.8.2
Uname: Linux 3.8.0-11-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.9.1-0ubuntu1
Architecture: amd64
Date: Sat Mar 9 06:31:24 2013
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2013-03-09 (0 days ago)
InstallationMedia: Xubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130308)
IpRoute:
 default via 192.168.1.1 dev eth1 proto static
 169.254.0.0/16 dev eth1 scope link metric 1000
 192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.111 metric 9
MarkForUpload: True
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 BlueSabreNet 67f55344-0f2f-4d59-895b-612c8b74340f 802-11-wireless 1362828481 Sat 09 Mar 2013 06:28:01 AM EST yes no /org/freedesktop/NetworkManager/Settings/1
 Wired connection 1 5360ee5e-3fe0-4e82-9fd5-3c9515c22ea6 802-3-ethernet 1362828374 Sat 09 Mar 2013 06:26:14 AM EST yes no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth1 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/1
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.0 connected enabled enabled enabled enabled disabled

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Antoine (tawane)]

I am affected by this bug, but not each time. If I disconnect then reconnect my ethernet cable, it works (even if it take a long time to detect disconnection and reconnection).

But when I tempoary lost my connection (it happen sometime in my office network), I can't reconnect anymore and I need to restart my computer.

The particular of my environment is that my user account is not registered on my system. When I log in, the check is done through the LDAP of my office. So when I lost the network, I can't use "sudo" in command line anymore. If I lock my desktop, I can't log in again. When it happen, I have to restart my computer to get back.

This never happened before I upgrade to raring.

Hope this will help you.

[Id2ndR (id2ndr)]

I have encountered this bug too when I unplug and plug back the network cable rapidly. A "workaround" of this trouble is to wait enough time (10 seconds) that network manager change it state *and* is ready to detect that ethernet link came up.

So, in order to reproduce :
- unplug the ethernet cable (or unplug network switch's power source)
- plug it back within 4-5 seconds (network manager should have the time to detect that the cable is unplugged but not enough to be ready to detect when the cable will be plugged back)
result : you will be disconnected

[Id2ndR (id2ndr)]

By the way: I have encountered this bug in Ubuntu 12.04.2

[Matthew Paul Thomas (mpt)]

This is similar to bug 1153545.