networking hosed after upgrading to 10.04

[Lucio M Nicolosi]

On Tue, May 31, 2011 at 12:48 AM, scar <scar at drigon.com> wrote:
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> i finally decided to upgrade an old machine from 9.10 to 10.04, and
> there is something strange going on with the networking.
>
> this machine is only connected to my LAN using one ethernet port, and i
> also had previously set up a bridge for use with a virtual machine i
> have installed, so a rather simple setup but not standard.  i just used
> the KVM setup guide on ubuntu.com somewhere to setup the bridge.
>
> when the system boots up, it can't be found on the LAN, and it can't
> connect to websites either.
>
> in network manager i have several different connections that i don't
> remember having:
>
> Wired connection 1
> Auto eth0
> Auto Ethernet
> ifupdown (eth0)
> ifupdown (br0)
>
> i'm pretty sure 'auto ethernet' was the only one i used before.  it
> seems after i pick any one of these to connect to, i then have access to
> my LAN, but still can't reach any outside websites for example.
>
> also, when i was running 9.10 my motherboard blew out and i had it
> replaced under warranty.  however, a different model was sent since the
> original had been discontinued.  i remember something strange happened
> with the networking at that time too, but i was able to get it working
> with some help from my loco team, and haven't had to fuss with it since.
>
> it seems to me this chain of events may have really messed up my
> networking (this system has been upgraded since 8.10 too).  i'm
> wondering if there is a simple way to wipe the slate clean and get my
> LAN and bridge connections configured again...

Perhaps you could run the Live CD (Lucid, Maverick or even Natty) and
if the network is correctly configured (as probably it will), copy the
settings to the HD install.

(Wouldn't you consider a brand new, clean, fresh install?)

-- 
Lucio M. Nicolosi, Eng.
Open Source Implementation
System and Applications
GNU/Linux