No Connection

[J]

On Fri, Apr 23, 2010 at 15:14, Ted Hilts <ehilts at mcsnet.ca> wrote:
> I have this Linux machine that suddenly lost it's connection to the
> Internet. I was running Lucid(installed) so I tried several other Ubuntu
> LIVE releases like Karmic Koaoa (9.10), Jaunty Jackalopes (9.04) but
> they all behaved in the same way -- that is NO CONNECTION.  Originally
> at the time of the failure I had  been using the LAN connection which is
> part of the CPU board.  So I removed the wire LAN cable from the socket
> and added a LAN Card which goes into the computer bus.  But the same
> problem persists.  All the LIVE machines still had the same problem --
> NO CONNECTION even though it was enabled.  I have tried shutting down
> and restarting. At first I thought the problem was hardware but the LAN
> card is okay -- I took it from another Linux computer.  So now I think
> something in the software is blocking the usual processes especially
> because there is absolutely NO output data coming out of the "route -n"
> command.

Silly question, but you see the same behaviour on several versions
(Karmic, Lucid and Jaunty), both live and installed.

Can your other computers get out to the internet?  Are you sure your
router/cable modem/network infrastructure is working?

Have you tried resetting your gateway (dsl router or cable modem)?

Just the basics there... if this were only happening on the Lucid
installation, I'd suspect you'd broken something, but since you say
you also booted the Live images for both Karmic and Jaunty (which will
NOT be affected to whatever changes you made to your Lucid install),
you need to look elsewhere for starters... (be it the hardware, cables
unplugged, router gone nuts, cable company cut a line, whatever).

How about this, foregoing any mucking with network settings, can you
plug this failing machine directly into your DSL router or cable modem
(means disconnecting the rest of your lan) and then boot the LIVE
image for any of those, get an address from your router or cable
modem, and surf the internet?

That would probably be my first step, after checking cables and such,
given what you've described.