network failure - hardware or software ??

English Network/Internet
1

Hello.
3 days ago I bought a used laptop to make test about virtualization.
HP Pavilion dv6-9530em
Intel® Core™2 Duo Processor T5450
(2M Cache, 1.66 GHz, 667 MHz FSB)
NVIDIA GeForce 8400M GS
Realtek High Definition Audio
Realtek RTL8168/8111 Family PCI-E Gigabit Ethernet NIC
Intel(R) PRO/Wireless 3945ABG Network Connection

Until now the network was working.

I decide to reinstall opensuse 12.1

I can set manually an adress z.x.y.40 (from the pool I have defined z.x.y.20 to z.x.y.50)
But the adress cannot be set by DHCP.

I get an error message
a) with traditional ifup : eth0 time out // eth0 link down
b) with network manager : eth0 link down // eth0 link is not ready // DHCPDISCOVER on eth0 to 255.255.255.255

The DHCP server is a netgear router RP614v3 which is configured to give adress within z.x.y.20 to z.x.y.50 and to set a fixed adress for the linux server and the printer.

On this site (home) there is one linux server (running opensuse 12.1) and 3 laptops (one running XP, one running win 7 pro and the new one running 12.1).

So what can I do?

2

Usually, “eth0 link down // eth0 link is not ready” indicates a cabling problem or a network interface card problem.

If there is only a “dhcp” failure, that will give a different message.

3

So why the laptop is connected to network if I set IP adress manually.
( As you can see I can post from my laptop).

So where to find the problem ?

4

There’s too little information to answer that.

Here’s my desktop experience, though it probably won’t help:

Previous desktop:

It defaulted to using “ifup” settings. I did switch the dhcp to using “dhclient”. I never had a network problem, other than that caused by a “dhclient” bug early in the 12.1 release cycle. If my router happened to reboot, I would notice at most a short network down time. After the router restarted, it kept working. It continued to use its existing DHCP lease.

For a while, I experimented with NetworkManager. When using NetworkManager, it would sometimes lose connection when the router rebooted. I had to “disable network” then “enable network” on the NetworkManager applet (in KDE). Naturally, I switched back to “ifup”.

Current desktop (as of only a couple of weeks). It is running 12.2 RC2, and the network uses “ifup”. My router rebooted a couple of days ago, and I lost connection. I had to unplug the cable, wait a few seconds, plug it in again, before the connection was restored. This seems to be due to a funky network card. The same box was previously used for Windows Vista, where it had similar problems with the network.