strange Ethernet problem

Hi all,

I installed Ubuntu 6.06 LTS from the CD on an old PowerPC Macintosh, and
got everything, including internet access, working okay. Then I updated
to 8.04 LTS. Now I can't get to the network! For url Firefox says
"address not found". For IP address it says "failed to connect ...
though seems to be valid".

Network Settings shows wired connection with "address: dhcp" but IP
address, DNS, etc. are blank. Network tools lists eth0 in menu and
shows an ipv6 address, but the hardware address, etc. are "not
available". The "received packets" count keeps going up!

If I boot to the 6.06 CD, Network settings does not even show wired
connection!

I use the built-in 100base-t connected to a router using DHCP.

Any clues how to fix or at least dignose?

TIA

On Sat, 05 Sep 2009 20:32:53 -0400, Erhardt Georg Kurzhals rearranged some
electrons to say:

> Hi all,
>
> I installed Ubuntu 6.06 LTS from the CD on an old PowerPC Macintosh, and
> got everything, including internet access, working okay. Then I updated
> to 8.04 LTS. Now I can't get to the network! For url Firefox says
> "address not found". For IP address it says "failed to connect ...
> though seems to be valid".
>
> Network Settings shows wired connection with "address: dhcp" but IP
> address, DNS, etc. are blank. Network tools lists eth0 in menu and
> shows an ipv6 address, but the hardware address, etc. are "not
> available". The "received packets" count keeps going up!
>
> If I boot to the 6.06 CD, Network settings does not even show wired
> connection!
>
> I use the built-in 100base-t connected to a router using DHCP.
>
> Any clues how to fix or at least dignose?
>
> TIA

Does your ISP support ipv6?

Moe Trin wrote:
> On Sat, 05 Sep 2009, in the Usenet newsgroup comp.os.linux.networking, in
> article <3225f$4aa30336$adbc7e0a$(E-Mail Removed)>, Erhardt Georg Kurzhals
> wrote:
>
>> ... SNIP ...
> Look at the output of the following commands
>
> cat /etc/resolv.conf
the file is empty
>
>
> /sbin/ifconfig -a
shows only inet6 fe80::...
>
> /sbin/route -n
shows nothing
>
.... SNIP ...
> Either a misconfigured DHCP client (I don't use DHCP), or server?
with the comments removed, dhclient.conf is:
send host-name "<hostname>";
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, host-name,
netbios-name-servers, netbios-scope;
timeout 30;

....SNIP ...
> Old guy
After this, I did some experiments. If I change from dhcp to
static IP, supplying a network compatible IPv4 address, subnet mask, and
the IP of my router, then I can visit websites I visited before, but not
any new sites. I then switch back to dhcp, and things work okay.
However, after I restart the computer it is back to the old problem.
Other possible clues:
1. I get "failed" for loading hardware drivers during boot, (and
something else that scrolls away before I can read it.)
2. Devices - Network Tools for eth0 shows in IP Information, both IPv4
(sensible) and IPv6 (fe80...), and in Interface Information, a sensible
Hardware address, but Link speed is "not available".

Erhardt Georg Kurzhals <(E-Mail Removed)> writes:

>Moe Trin wrote:
>> On Sat, 05 Sep 2009, in the Usenet newsgroup comp.os.linux.networking, in
>> article <3225f$4aa30336$adbc7e0a$(E-Mail Removed)>, Erhardt Georg Kurzhals
>> wrote:
>>
>>> ... SNIP ...
>> Look at the output of the following commands
>>
>> cat /etc/resolv.conf
>the file is empty

Well, that means that no address can be resolved unless it is in your
/etc/hosts file. Why is it empty?


>>
>>
> > /sbin/ifconfig -a
>shows only inet6 fe80::...

It sounds like you do not really have a connection.


>>
>> /sbin/route -n
>shows nothing

And why in the world do you not actually post all of the output here.
What is nothing to you may be critical info to us. For example there
should be local (lo) routes.


>>
>... SNIP ...
>> Either a misconfigured DHCP client (I don't use DHCP), or server?
>with the comments removed, dhclient.conf is:
>send host-name "<hostname>";

>request subnet-mask, broadcast-address, time-offset, routers,
> domain-name, domain-name-servers, host-name,
> netbios-name-servers, netbios-scope;
>timeout 30;

>...SNIP ...
>> Old guy
> After this, I did some experiments. If I change from dhcp to
>static IP, supplying a network compatible IPv4 address, subnet mask, and
>the IP of my router, then I can visit websites I visited before, but not
>any new sites. I then switch back to dhcp, and things work okay.
>However, after I restart the computer it is back to the old problem.
> Other possible clues:
>1. I get "failed" for loading hardware drivers during boot, (and
>something else that scrolls away before I can read it.)

dmesg|less

>2. Devices - Network Tools for eth0 shows in IP Information, both IPv4
>(sensible) and IPv6 (fe80...), and in Interface Information, a sensible
>Hardware address, but Link speed is "not available".

Hello,

Moe Trin a écrit :
> Erhardt Georg Kurzhals wrote:
>
>>> cat /etc/resolv.conf
>> the file is empty
>
> Thus, your O/S has no idea _who_ to ask to resolve addresses.

Yes it does. When the file is empty, it assumes the nameserver is localhost.

>>> /sbin/ifconfig -a
>> shows only inet6 fe80::...
>
> Interface not being configured - the 'fe80::' address is basically an
> "I don't have a real address, so I'll use this".

Not really. This is just the autoconfigured IPv6 link-local address
which is mandatory on any IPv6-enabled interface.

> These addresses,
> like 169.254.x.x are set when the system can't contact a DHCP server.

Not really. They are both link-local addresses, but if 169.254.x.x are
mostly associated to DHCP failure, fe80:: are not.

> Like the RFC1918 addresses, these must never appear on the Internet,
> and thus are "local use only".

Worse : link-local addresses are not routable, whereas private addresses
are routable (on a private network only of course).