Thanks for that, but that's where I started.
I finally found an e1000 network card and that didn't work either.
I conclude that I have a faulty motherboard, because others have reported the same issue and also failure of usb 2.0 ports, which I also have.

Regards
Bill Maidment
Maidment Enterprises Pty Ltd

N.B. Any email disclaimer in the original message has been carefully ignored as it has no meaning in law.

-----Original message-----
From: Paul Robert Marino<[log in to unmask]>
Sent: Sunday 5th May 2013 15:33
To: Bill Maidment <[log in to unmask]>; [log in to unmask]
Subject: Re: Netrwork dropping transmitted packages on fresh SL 6.4 install

Elrepo is your problem they often push untested updated drivers.
Use the drivers that came with the kernel they may not have all the features but they should work.
Do not install kmod-8169.

-- Sent from my HP Pre3

-----------
On May 4, 2013 4:11 AM, Bill Maidment <[log in to unmask]> wrote:

Hi again
I've just rebuilt a desktop machine with a GA-970A-D3 motherboard using SL 6.4 64 bit isos and the network adaptor is dropping all transmitted packages.
The onboard adapter is a Realtek RTL8168/8111
Using a Fedora 18 Live disk the network adapter works OK and is recognised as RTL8168evl/8111evl
I have other spare network cards, but the are all RTL8168 or RTL8169 and all show the same symptoms in SL 6.4, but they all work in Fedora 18.
Can anyone help me to get the drivers updated (ELrepo kmod-r8168 and kmod-r8169 did not help)?