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I'm using a wired network connection that should be manually configured. Which is working in my parallel boot Windows XP. But in my Ubuntu 10.10 after giving same values of IP address, subnet Mask, Default Gateway and DNS Servers the wired network connection is shown as active but Firefox is not detecting any connection.

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How did you configure your connection?? – karthick87 Dec 19 '10 at 7:56
yes i did . after that it showed network connection active.. – Tony John Dec 19 '10 at 8:00
can you post the output of ifconfig – karthick87 Dec 19 '10 at 8:00
from top Network icon . edit network connection... – Tony John Dec 19 '10 at 8:01
eth0 Link encap:Ethernet HWaddr 00:e0:1c:3b:da:0a inet addr: Bcast: Mask: inet6 addr: fe80::2e0:1cff:fe3b:da0a/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:9829 errors:2 dropped:0 overruns:0 frame:0 TX packets:543 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1547519 (1.5 MB) TX bytes:119509 (119.5 KB) Interrupt:19 Base address:0xb800 – Tony John Dec 19 '10 at 8:02

I would suspect that your subnet mask is set wrong. The 192.168.x.x range of addresses are normally set up as class C networks with a mask of It won't work correctly if you have it set wrong.

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Is your Firefox working online? Sometimes it switches to offline and don't back to online. Check if your File > Work Offline menu is unchecked.

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Try manually setting an IP address for your device.

It looks like your broadband router is, so follow these steps :

  1. Right click on the network manager applet and choose "Edit Connections..."
  2. In the "Wired" tab, click the "Add" button.
  3. Enter a Connection Name like "My Manual Connection"
  4. Click on the IPv4 Settings tab.
  5. Change the "Method" to "Manual".
  6. Under "Addresses" click on "Add"
  7. Put for Address. Put for Netmask. Put for Gateway.
  8. For nameserver, put and (the second address is openDNS, a free DNS server that anyone can use).
  9. Click on the "Add" button at the bottom.
  10. Now activate your newly created profile - left click on the network manager applet, then choose your newly created connection.

Now try pinging your gateway with ping You should see something like this :

scaine@GroovyTosh:~$ ping
PING ( 56(84) bytes of data.
64 bytes from icmp_req=1 ttl=255 time=0.378 ms
64 bytes from icmp_req=2 ttl=255 time=0.358 ms
64 bytes from icmp_req=3 ttl=255 time=0.546 ms

If this works, then you have an issue with your DHCP server which is issuing incorrect CLASS B ( subnet masks and might not be setting your default route correctly.

However, if this does work, then you should be able to run with this configuration without any issues.

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