I recently installed a fresh Ubuntu 12.04 LTS on a desktop, and the installation itself was successful (other than 'grub rescue' issue that I encountered but fixed) but this connection problem is really giving me a headache.

Symptoms: 1. When I open the FireFox browser and try to connect to a website, it just hangs for a while saying "Connecting..." but eventually loads an error page "The connection has timed out". 2. It's not a browser problem (and I tried setting ipv6 thing to "true" at about:config) because running "sudo apt-get install [some-random-package]" at terminal fails ("E: Unable to locate package [package]") too. All other operations that need internet access are not working. 3. I certainly see a wired network (called "eth1") at the Network Manager, and it says "Connection Established" after disconnecting and then connecting again.

I have tried almost everything that could be found from google search results still no luck. Their problems slightly differ from mine or the solutions just don't work.

By the way it didn't have internet access when installing Ubuntu 12.04. (I ignored the message that I need internet to install Ubuntu) Could this be a problem? I'm sorry I don't remember if internet worked or not on the previous version of Ubuntu. :(

I would really appreciate your help... I don't even know what more to do if this fails too.. Thanks!!

Thanks for your comment. Here is the result of ifconfig:

eth0      Link encap:Ethernet  HWaddr 78:ac:c0:3d:b2:b9  
          inet addr:10.10.65.185  Bcast:10.10.65.255  Mask:255.255.255.0
          inet6 addr: fe80::7aac:c0ff:fe3d:b2b9/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3907 errors:0 dropped:0 overruns:0 frame:0
          TX packets:771 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:393118 (393.1 KB)  TX bytes:73472 (73.4 KB)
          Interrupt:16 

eth1      Link encap:Ethernet  HWaddr 78:ac:c0:3d:b2:b8  
          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 

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:4 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:204 (204.0 B)  TX bytes:204 (204.0 B)

route -n:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.10.65.1      0.0.0.0         UG    0      0        0 eth0
10.10.65.0      0.0.0.0         255.255.255.0   U     1      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0

/etc/resolv.conf:

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 10.81.1.8
nameserver 10.1.2.10
nameserver 127.0.0.1
search yamatake.local

/etc/network/interfaces:

auto lo
iface lo inet loopback

#auto eth0
#iface eth0 inet dhcp

#auto eth1
#iface eth1 inet dhcp

And I'll also include the result of 'sudo lshw -C network' in case it might help:

  *-network
       description: Ethernet interface
       product: NetXtreme BCM5764M Gigabit Ethernet PCIe
       vendor: Broadcom Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: eth0
       version: 10
       serial: 78:ac:c0:3d:b2:b9
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.121 duplex=full firmware=5764m-v3.35 ip=10.10.65.185 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:93 memory:fc000000-fc00ffff
  *-network
       description: Ethernet interface
       product: NetXtreme BCM5764M Gigabit Ethernet PCIe
       vendor: Broadcom Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       logical name: eth1
       version: 10
       serial: 78:ac:c0:3d:b2:b8
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.121 duplex=full firmware=5764m-v3.35 latency=0 link=no multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:94 memory:fb000000-fb00ffff