ethernet disconnected, shows up in ifconfig
Solution 1
Edit the interfaces file to remove
auto eth0
iface eth0 inet dhcp
Save and restart. Use Network manager to edit the connection and set it to automatically connect.
This command will open the interfaces file in Gedit with permission to save the file:
sudo gedit /etc/network/interfaces
I have both a wired and a wireless connection and all that is in my interfaces file is these two lines
auto lo
iface lo inet loopback
I have found from experience than anything else will prevent a connection and removing what is extra will solve the problem.
Solution 2
Basic layer 1 ground check - is your ethernet port connected and are you sure the wire and modem port are fine? Please confirm that the ethernet port light blinks (either green or amber) when you connect the wire. Otherwise it is a physical layer issue. Does it work on other machines at the same swtich-port?
Assuming the above is taken care of, Have you tried
sudo ifconfig eth0 up
?Also, check your
/etc/network/interfaces
file and see if the following line is thereauto eth0
This automatically enables eth0 on startup
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tekknolagi
Updated on September 18, 2022Comments
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tekknolagi about 1 year
I am running 11.04, no remix. After installation, I could use wireless networks, but not ethernet. When I click on the connections menu item, it says
Wired Network disconnected
How do I fix this?
Here is the ethernet portion of
ifconfig
:eth0 Link encap:Ethernet HWaddr 00:16:36:86:f3:43 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:17
And the result of
lspci
:00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03) 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03) 00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03) 00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 01) 00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 01) 00:1d.0 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 (rev 01) 00:1d.1 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 01) 00:1d.2 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 01) 00:1d.3 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 01) 00:1d.7 USB Controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 01) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1) 00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 01) 00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01) 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5788 Gigabit Ethernet (rev 03) 02:09.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller 02:09.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant IEEE 1394 Host Controller 02:09.4 Communication controller: Texas Instruments PCIxx12 GemCore based SmartCard controller 08:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Net
My
/etc/network/interfaces
looks like this:auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp
And I get no output from
sudo ifconfig eth0 up
.Output from
nm-applet
:** (nm-applet:1824): DEBUG: old state indicates that this was not a disconnect 0 ** (nm-applet:1824): DEBUG: old state indicates that this was not a disconnect 0
On second run of
nm-applet
:** (nm-applet:2752): DEBUG: old state indicates that this was not a disconnect 0 ** (nm-applet:2752): DEBUG: old state indicates that this was not a disconnect 0 ** (nm-applet:2752): WARNING **: _nm_object_get_property: Error getting 'WpaFlags' for /org/freedesktop/NetworkManager/AccessPoint/10: (19) Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist ** (nm-applet:2752): WARNING **: _nm_object_get_property: Error getting 'RsnFlags' for /org/freedesktop/NetworkManager/AccessPoint/10: (19) Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist ** (nm-applet:2752): WARNING **: Error in getting active connection 'Vpn' property: (19) Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist ** (nm-applet:2752): WARNING **: _nm_object_array_demarshal: couldn't create object for /org/freedesktop/NetworkManager/ActiveConnection/0 ** Message: <info> No keyring secrets found for Auto HeyJude88/802-11-wireless-security; asking user. ** (nm-applet:2752): WARNING **: applet.c.2882 (applet_settings_new_secrets_requested_cb): couldn't find details for connection ** Message: <info> No keyring secrets found for Auto HeyJude88/802-11-wireless-security; asking user. ** (nm-applet:2752): DEBUG: going for offline with icon: notification-network-wireless-disconnected ** (nm-applet:2752): DEBUG: foo_client_state_changed_cb ** (nm-applet:2752): DEBUG: foo_client_state_changed_cb ** (nm-applet:2752): DEBUG: foo_client_state_changed_cb ** (nm-applet:2752): DEBUG: going for offline with icon: notification-network-wireless-disconnected ** (nm-applet:2752): DEBUG: foo_client_state_changed_cb
Here's more to
ifconfig
:wlan0 Link encap:Ethernet HWaddr 00:18:de:31:70:20 inet addr:172.16.6.210 Bcast:172.16.6.255 Mask:255.255.255.0 inet6 addr: fe80::218:deff:fe31:7020/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2384 errors:0 dropped:0 overruns:0 frame:0 TX packets:1367 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:514654 (514.6 KB) TX bytes:215138 (215.1 KB)
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Allan about 12 yearsCan you run this command
killall -9 nm-applet
followed bynohup nm-applet &
this should create a file called nohup.out in your home folder can you add the contents if any to your question -
tekknolagi about 12 yearsIs nm network manager? What will this be doing?
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tekknolagi about 12 yearssee my edit for details
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Allan about 12 yearsthe commands will stop and restart network manager applet when you do this it will search for available connections and output messages to the nohup.out file.
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tekknolagi about 12 yearsJust posted the output. That's all there is.
1824
is the pid. -
tekknolagi about 12 yearsran it a second time, more output
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ivotron over 10 yearsfor the record, in my case, the
eth0
entry in the/etc/network/interfaces
appears because I had installedubuntu-server
on my machine and then installedubuntu-desktop
and thus the network manager can't "see" the interface
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tekknolagi about 12 yearssee my edit for details
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tekknolagi about 12 yearsI still get
Wired Networks \n disconnected
in the menu tray -
tekknolagi about 12 yearsadded some more output from
ifconfig
, hope it's useful -
Sudipta Chatterjee about 12 yearsRight click on the network manager icon and see if "Enable networking" icon is enabled
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tekknolagi about 12 yearsEnabled... Wireless works.
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Admin almost 12 yearsThis works for me, but the problem reappears whenever I shutdown while connected to a wireless network, then start back up without being connected to a network. I'm not able to connect to any Wi-Fi hot-spots until I perform these steps.