From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthias Leopold <matthias.leopold@meduniwien.ac.at>
Subject: network problems
Date: Fri, 20 May 2016 18:19:24 +0200
Message-ID: <573F390C.20108@meduniwien.ac.at>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8;
	format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE
To: kvm@vger.kernel.org
Return-path: <kvm-owner@vger.kernel.org>
Received: from mailsip.srv.meduniwien.ac.at ([149.148.51.14]:47995 "EHLO
	smtpi.meduniwien.ac.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1754840AbcETQ2A convert rfc822-to-8bit (ORCPT
	<rfc822;kvm@vger.kernel.org>); Fri, 20 May 2016 12:28:00 -0400
Received: from localhost (localhost [127.0.0.1])
	by smtpi.meduniwien.ac.at (Postfix) with ESMTP id 2B07E60428
	for <kvm@vger.kernel.org>; Fri, 20 May 2016 18:19:43 +0200 (CEST)
Received: from smtpi.meduniwien.ac.at ([127.0.0.1])
	by localhost (mailsip.meduniwien.ac.at [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id ZoI2mJ3PFPln for <kvm@vger.kernel.org>;
	Fri, 20 May 2016 18:19:42 +0200 (CEST)
Received: from [149.148.52.63] (itsc063.cc.meduniwien.ac.at [149.148.52.63])
	by smtpi.meduniwien.ac.at (Postfix) with ESMTPS id 3E5B360084
	for <kvm@vger.kernel.org>; Fri, 20 May 2016 18:19:42 +0200 (CEST)
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

hi,

today i set up my first kvm guest, a centos 7 machine on a centos 6 kvm=
=20
host. there are already 3 guests (centos 6) running (not set up by me).=
=20
as far as i can see the setup is "the same", problem is as soon as i=20
start the network in the guest the host physical interface goes down:=20
"e1000e: eth0 NIC Link is Down". i'm using bridged networking, network=20
driver in the guest is virtio. when i use "e1000" driver in the guest=20
already starting the guest brings the host interface down. what could b=
e=20
wrong?

network on the kvm host is maybe a bit special as there are 3 physical=20
interfaces altogether, one of them consists of two bonded SFP=20
interfaces. the 3 "old" kvm guests use these interfaces in bridge mode=20
with no problems. but they are centos 6, the new one is centos 7... is=20
there a difference?

dmesg says:

device vnet9 entered promiscuous mode
br0: port 5(vnet9) entering forwarding state
vnet9: no IPv6 routers present
kvm: 11206: cpu0 disabled perfctr wrmsr: 0xc2 data 0xffff
e1000e: eth0 NIC Link is Down
br0: port 1(eth0) entering disabled state
br0: port 5(vnet9) entering disabled state
device vnet9 left promiscuous mode
=2E..

guest network configuration

     <interface type=3D'bridge'>
       <mac address=3D'52:54:00:67:36:89'/>
       <source bridge=3D'br0'/>
       <model type=3D'virtio'/>
       <address type=3D'pci' domain=3D'0x0000' bus=3D'0x00' slot=3D'0x0=
3'=20
function=3D'0x0'/>
     </interface>

thx
matthias

--=20
Matthias Leopold
IT Systems & Communications
Medizinische Universit=C3=A4t Wien
Spitalgasse 23 / BT 88 /Ebene 00
A-1090 Wien
Tel: +43 1 40160-21241
=46ax: +43 1 40160-921200