This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] Multiple Network Cards + Multiple Bridges on debian lenn

To: "Fajar A. Nugraha" <fajar@xxxxxxxxx>, xen-users <xen-users@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] Multiple Network Cards + Multiple Bridges on debian lenny
From: Alexander Pirsig <alex@xxxxxxxxxx>
Date: Mon, 31 Aug 2009 10:25:04 +0200
Delivery-date: Mon, 31 Aug 2009 01:25:43 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <7207d96f0908302354x6eea844ck803864c11b08a6d0@xxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4A9AFD72.9050807@xxxxxxxxxx> <20090830231420.GA32451@xxxxxxxxxxxxxxxxxxx> <4A9B6C5E.8000800@xxxxxxxxxx> <7207d96f0908302354x6eea844ck803864c11b08a6d0@xxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (X11/20090817)
Hi Fajar,

I think it could be the conntrack tables but at the moment its hard tell because the system load is back to normal.

At the moment my conntrack table and settings look like this:

cat /proc/sys/net/ipv4/netfilter/ip_conntrack_max

cat /proc/net/ip_conntrack | wc -l

I wonder about your vif-script though. Why do you have it commeted
out? Which vif-script did you use?
# (vif-script vif-bridge)
The answer to this question is:

cat /etc/xen/scripts/vif-bridge | head
# /etc/xen/vif-bridge
# Script for configuring a vif in bridged mode.
# The hotplugging system will call this script if it is specified either in
# the device configuration given to Xend, or the default Xend configuration
# in /etc/xen/xend-config.sxp.  If the script is specified in neither of those
# places, then this script is the default.

So that means if you comment out vif-bridge vif-bridge is used via default in Debian.

I just wonder because in our application we're getting a large amount of different Ip's. A normal client connect takes 0.3ms and then they are gone :) probably I'll should raise conntrack table settings.



Fajar A. Nugraha wrote:
On Mon, Aug 31, 2009 at 1:23 PM, Alexander Pirsig<alex@xxxxxxxxxx> wrote:

Bridge config on Dom0 looks like this:

xenbr1          8000.001b213b8a69       no              eth1

Yesterday I discovered that sometimes during Highload on DomU's part of the
network is hard rechable with ssh or connections stalls even if I try to
connect to dom0 with has seperate uplink.

There was a thread on this list sometime ago, regarding iptables. Do
you have /proc/net/ip_conntrack on dom0? Does the number of lines
close to /proc/sys/net/ipv4/netfilter/ip_conntrack_max?

checking arp sometimes shows strange information (during highload) like:

arp -na
? ( at 00:1b:21:3b:8a:68 [ether] on eth0
? ( at 00:1b:21:3b:8a:68[ether] on xenbr1

So my question are:

1. Is it normal that bridge xenbr1 claims ip mac address of eth1?


2. Do I have to reset mac address on the bridge (xenbr1) or network
interface (eth1) to FF:FF:FF:FF bevor starting it.

Not really. Your standard bridge setup using OS init scripts should
work. That's what I use, with RHEL.

3. What could cause the problem with the arp table?
4. Do I have to turn of  arp/multicast on eth1 or xenbr1 like this ->
  ip link set xenbr1 arp off
  ip link set xenbr1 multicast off

I'm not sure about these two. I don't arp and multicast use their
default settings on RHEL, YMMV.
Since you mention "high load" I suspect it has something to do with
iptables connection tracking.

I wonder about your vif-script though. Why do you have it commeted
out? Which vif-script did you use?
# (vif-script vif-bridge)

Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>