Problems with networking

In "Device Manager" I can't see anything wrong with my 3Com card/drivers, but... The led in my router is not active, so something is wrong, and it is not the cable... I also noticed that when trying to use dhcp, I get IPv 6, not 4... Why, and can that be my problem?

Regards Geir Sørensen, Norway.

Dear,
Please open Applications > System Tools > Root Terminal
try this command
# ifconfig
you should be able to see "eth0" and "lo" as you have said you can ping your own IP.

I suggest you try any one of following:

1. Try to turn off zonealarm on one of other PCs and ping your pc from there.
2. Try to change the NetworkCard (If you have spare one)
3. System > Administration > Networking try to Activate the eth0 and then set it as your default gateway device.

I would need some further information about your DHCP Server, your IP and subnetmask and the brand and type of router you are using.

HI.
Thanks for your reply!
I have checked #ifconfig, and as far as I can see everything is ok here... But I did thing about the networkcard, because it worked a few weeks ago..... Installed Linux on another pc with a nic on the motherboard. Everything workes fine here, so I guess I just have to buy me another nic for my "problem-pc".

Again! Thanks!
Regards Geir.

I have had EXACTLY the same problem with Ubuntu 5.10 on an older Digital PC. With a little experimentation, I have discovered the following:

1) The NIC in the PC is and 10/100Mb/S auto adaptive.
2) I configured the NIC for IP statically.
3) The old hub it is attached to is 10Mb/S only, not auto-adaptive.
4) The NIC fails to connect to the rest of my network, I cannot even ping the router.
5) Without changing any settings, I plugged the network cable directly to my router, a 100Mb/S unit.
6) Connection works! All good and fully function!

My conclusion: Ubuntu does not allow the auto-adaptive NIC to auto-adapt. Instead, it "fixes" it at the maximum speed.

Follow-up research: There appears no simple way to override/force NIC adaptive speed behaviour in Ubuntu. Currently, I have not found a more arcane Linux way either...

try
 sudo ethtool -s eth0 speed 10
or maybe
 sudo ethtool -s eth0 duplex half speed 10

The above issue is essentially the same as on my machine. One issue I am having is that i can connect to the internet or ping a local host for about 30 seconds, then my connection drops. I do not have this issue with Etch or NT so I am kinda stumped. I have my card configured with a static ip address. I am able to ping the loopback no problem. When I loaded the live CD I was able to get to the internet and browse with no problems. Looking in the messages logs I only find "link is not ready" and "link becomes ready" then "link is not ready" again. The card came with my Dell pc. Is is a Davicom DM9102/DM9102A rev 49. Why my connection can connect then disconnect is a mystery to me at this point

Howdy,
  I can only add that I have seen this behavior with an Iwill P4 small system. It seems to be sensitive as to what switch I plug it into. With some switches, it acts like yours and I can't get anything done. I carry around a usb nic for emergencies, and at home switched to another switch and it worked fine.
Good luck.