installer does not find a network - but a live system does ... wtf?

[Andi Meier]

On 14.03.2011 17:30, Steven Susbauer wrote:
> I experienced a similar issue to this when installing 10.4 in the
> past. Is this a wired or wireless network? Does the interface show up
> in ifconfig? Any messages in dmesg?

The network is connected via the on-board ethernet LAN connector (no WLAN, but "wired" LAN).

When I boot via 10.04 live (working), I can see two relevant lines in dmesg:

  line 620: [    6.705042] eth0: RTL8168d/8111d at 0xffffc90000332000, 00:26:18:f0:1d:43, XID 083000c0 IRQ 26
  line 756: [   40.718638] r8169: eth0: link up

However, after booting from hard disk, the related lines in dmesg are:

  line 606: [    1.518272] eth0: RTL8168d/8111d at 0xffffc9000291e000, 00:26:18:f0:1d:43, XID 083000c0 IRQ 26
  line 719: [    6.426029] r8169: eth0: link down

Note that it says "link down". Now it would be interesting what causes Ubuntu to think that the interface is down?

I should also note that I never really configured the network on installing onto hard disk or in the Live system. Instead, I always let the
installer/loader just find the DHCP data itself - this has always worked.

Even more info: the system 10.04 server 64-bit - which has this weird network problems - has actually been installed a few months ago on
this PC and used to work flawlessly, no issues at all never ever with the network. Then I tried to upgrade to 10.10 and then switched back
to 10.04. Since then, I have this network problem.

Cheers,
Andi