Networking Broken in Ubuntu 10.04 after applying updates from Update Manager

Please press space at Ubuntu boot and please select the previuos release of the kernel (3.rd row from the top) and boot from it...
It is working now...?

I have tried this -- See above "I have tried booting from an earlier version of the kernel (using the grub boot menu) but problem remains the same."

Can you give the output of:

sudo lshw -C network

Thanks

Oh! sorry please open a terminal and copy and paste the result of this commands, type:

(when you use the sudo command below, the system will ask you for a password, give your user password when requested, you don't see nothing when you type it, then press enter)

ifconfig -a

sudo dhclient

ifconfig -a

Homework completed:

bryan@tardis:~$ sudo lshw -c network
[sudo] password for bryan:
  *-network
       description: Ethernet interface
       product: RTL8111/8168B PCI Express Gigabit Ethernet controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eth0
       version: 03
       serial: 6c:f0:49:02:c5:19
       size: 10MB/s
       capacity: 1GB/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s
       resources: irq:32 ioport:de00(size=256) memory:fbdff000-fbdfffff(prefetchable) memory:fbdf8000-fbdfbfff(prefetchable) memory:fbd00000-fbd1ffff(prefetchable)

bryan@tardis:~$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 6c:f0:49:02:c5:19
          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:32 Base address:0x8000

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:40 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2488 (2.4 KB) TX bytes:2488 (2.4 KB)

bryan@tardis:~$ sudo dhclient
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/6c:f0:49:02:c5:19
Sending on LPF/eth0/6c:f0:49:02:c5:19
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 1
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

bryan@tardis:~$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 6c:f0:49:02:c5:19
          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:32 Base address:0x8000

eth0:avahi Link encap:Ethernet HWaddr 6c:f0:49:02:c5:19
          inet addr:169.254.6.26 Bcast:169.254.255.255 Mask:255.255.0.0
          UP BROADCAST MULTICAST MTU:1500 Metric:1
          Interrupt:32 Base address:0x8000

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:56 errors:0 dropped:0 overruns:0 frame:0
          TX packets:56 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:3464 (3.4 KB) TX bytes:3464 (3.4 KB)

bryan@tardis:~$

Please tell something about your network topology do you have a router connected with ethernet cable to your single pc...?

if yes

a) please entirely switch off your router
b) please entirely switch off your pc
c) please check: plug out and plug in your ethernet cable from router and pc plug
d) switch your router on
wait 1/2 minutes
e) switch your pc on

Please tell if it works now...

My PC is connected by a single ethernet cable to a Netcom NB6Plus4w Modem/Router.

I will do this, but please note that I am typing this from exactly the same PC, but booted up from an Ubuntu live CD. To answer your questions I need to shut this instance of Ubuntu (loaded from a CD), and then reboot from the hard disk.

This worked, but why did it work. One of this things which I originally did before raising the question was to turn the modem on and off. The only thing different was turning my PC completely off and on and unplugging the Ethernet cable.

Sometimes dhcp fail this usually is caused from communications between the pc and router... so this is the first try to do...

Now i suggest you also to disable ipv6...

Edit /etc/default/grub file from terminal type:

gksudo gedit /etc/default/grub

Change the row:

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”

and add the ipv6.disable=1 parameter

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash ipv6.disable=1”

Save and exit the file

Update the grub still using terminal type:

sudo update-grub

Then reboot your pc.

To increase Firefox speed try this little http://www.elart.it/mozilla/speedup.php

Hth