Ubuntu: Cannot access Internet after 14.04 upgrade


I upgraded from 13.10 to 14.04 a couple of days ago via internet using "sudo apt-get upgrade".

After the upgrade, both my wired connection and wireless connection stopped talking to the internet when using Firefox or Chrome.

I do not have any problem exchanging files with another PC (running Ubuntu 10.04) use Filezilla within the same network and am able to use Firefox to log into my router to check configuration.

What is so strange was the system appeared to be able to reach out to internet to download files when I run "sudo apt-get update".

I am really baffled by this. Any help to get me back my internet access for both wired/wireless connections would be appreciated.

Here's some information about my settings (wireless intentionally disabled when this snapshot is taken):

The unit is a ThinkPad T60.  ifconfig:  eth0  Link encap:Ethernet  HWaddr 00:15:58:7d:17:04          inet addr:  Bcast:  Mask:        inet6 addr: fe80::215:58ff:fe7d:1704/64 Scope:Link        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1        RX packets:162 errors:0 dropped:0 overruns:0 frame:0        TX packets:167 errors:0 dropped:0 overruns:0 carrier:0        collisions:0 txqueuelen:1000         RX bytes:50700 (50.7 KB)  TX bytes:24254 (24.2 KB)        Interrupt:16 Memory:ee000000-ee020000     lo    Link encap:Local Loopback          inet addr:  Mask:        inet6 addr: ::1/128 Scope:Host        UP LOOPBACK RUNNING  MTU:65536  Metric:1        RX packets:228 errors:0 dropped:0 overruns:0 frame:0        TX packets:228 errors:0 dropped:0 overruns:0 carrier:0        collisions:0 txqueuelen:0         RX bytes:57669 (57.6 KB)  TX bytes:57669 (57.6 KB)    sudo lshw -C network:  *-network                       description: Ethernet interface        product: 82573L Gigabit Ethernet Controller        vendor: Intel Corporation        physical id: 0        bus info: pci@0000:02:00.0        logical name: eth0        version: 00        serial: 00:15:58:7d:17:04        size: 100Mbit/s        capacity: 1Gbit/s        width: 32 bits        clock: 33MHz        capabilities: pm msi pciexpress bus_master cap_list ethernet physical tp 10bt    10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=2.3.2-k duplex=full firmware=0.5-1 ip= latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s        resources: irq:45 memory:ee000000-ee01ffff ioport:3000(size=32)   *-network DISABLED        description: Wireless interface        product: PRO/Wireless 3945ABG [Golan] Network Connection        vendor: Intel Corporation        physical id: 0        bus info: pci@0000:03:00.0        logical name: wlan0        version: 02        serial: 00:18:de:b8:b1:c2        width: 32 bits        clock: 33MHz        capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless        configuration: broadcast=yes driver=iwl3945 driverversion=3.13.0-24-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11abg        resources: irq:47 memory:edf00000-edf00fff      route -n  (revised using dhcp):  Kernel IP routing table  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface         UG    0      0        0 eth0   U     1      0        0 eth0   U     9      0        0 wlan0  


  1. In /etc/NetworkManager/NetworkManager.conf, change managed=false to managed=true.
  2. From the top-right corner select Edit Connections, and add a new connection. Specify your ip address, netmask, gateway, and the DNS server being
  3. Then run: sudo service network-manager restart.


Edit correctly the following files:

/etc/network/interfaces  /etc/resolv.conf  /etc/hosts  

In /etc/network/interfaces specify these information:

 auto ethX      iface ethX inet static        address      netmask      broadcast      dns-nameserver      gateway  

ethX: X can be 0,1, 2 ... depending on the network interface you are using. But in your case it is eth0

In /etc/resolv.conf specify these information:

nameserver x.x.x.x  

(you can add a new nameserver address on a new line)

In /etc/hosts add your username and address on the 3rd line as follows:

  yourUsername yourIPaddress  

After you saved the 3 files, run this command:

sudo service network-interface restart INTERFACE=eth0  


After several tinkering of the settings with helps from various readers here, the situation had not been improved.

So, I eventually backed up all the important files and did a full install of 14.04. Now the system is capable of getting to the internet and internal networks. There are, however, a few "glitches" in 14.04 gnome comparing to 13.10. But at least I can use my system again.

Thank you for those who lent a helping hand.


I had the same problem with my WiFi connection , I tried to edit Newtworkmanager.conf but didn't work for me .

I went to edit connection and deleted my Wifi connection Then added it again and entered the password ...

and It fortunately work :)

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
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