"Wired Network Disconnected" even when connected- no ethernet connection possible

Question

I am unable to connect to the internet via Ethernet or WiFi. Let's fix the Ethernet issue, eh? I just installed Ubuntu 12.04 on an HP Mini 1000. Previously it had 11.04, and the Ethernet didn't have any issues then. I am a Linux beginner, and I have been working on this issue for the past several days without any progress.

Here are some outputs:

$ sudo lshw -C network
*-network               
   description: Network controller
   product: BCM4312 802.11b/g LP-PHY
   vendor: Broadcom Corporation
   physical id: 0
   bus info: pci@0000:01:00.0
   version: 01
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress bus_master cap_list
   configuration: driver=b43-pci-bridge latency=0
   resources: irq:16 memory:feafc000-feafffff
*-network
   description: Ethernet interface
   product: 88E8040 PCI-E Fast Ethernet Controller
   vendor: Marvell Technology Group Ltd.
   physical id: 0
   bus info: pci@0000:02:00.0
   logical name: eth0
   version: 00
   serial: 00:25:b3:48:e7:60
   capacity: 100Mbit/s
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.30 latency=0 link=no multicast=yes port=twisted pair
   resources: irq:42 memory:febfc000-febfffff ioport:ec00(size=256)

lspci

00:00.0 Host bridge: Intel Corporation Mobile 945GSE Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GSE 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 02)
00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 2 (rev 02)
00:1d.0 USB controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 (rev 02)
00:1d.1 USB controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 02)
00:1d.2 USB controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 02)
00:1d.3 USB controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 02)
00:1d.7 USB controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation N10/ICH 7 Family SMBus Controller (rev 02)
01:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)
02:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8040 PCI-E Fast Ethernet Controller

Thanks for your help!

Solution 1

Found the solution:

In /etc/NetworkManager/NetworkManager.conf, I changed managed=false to managed=true.

Then run:

sudo service network-manager restart

and voila.

Solution 2

Mine got fixed from changing from 100mbps lan4 port to 100/1000mbps lan1 which is the fastest one, hope this helps

Comments

[Mina Michael]

try going to "software and updates" (from the dash) then go to the tab where there are proprietary drivers; if you find any that are disabled enable them.

[ricky]

Unfortunately, this screen doesn't show any available proprietary drivers since I do not have a network connection.

[ricky]

The link you sent me to requires me to install a package... which I can't do as I have no network connection. Also, I am unable to connect via wifi through terminal any other way as there is no logical name for my wlan card as you can see in my lshw -C network.

[Rohith Madhavan]

This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post.

[web.learner]

@RohithMadhavan How is this not an attempt to answer the question?

[Miguel Mota]

Had same issue on Fedora and sudo service NetworkManager restart worked for me

[LMSingh]

@RohithMadhavan this answer helped me, not fully but gave me some clues. It adds value to resolving this issue. As another answer says "sometimes NetworkManager can be a bit of a diva".. so any clues are helpful. Besides downvoting new users that are trying to be helpful is not encouraging for better contributions from them in the future.