<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Thanks a lot for you explanation Benoit<br>
I hope OpenVZ developers will take this in account.<br>
<br>
Regards.<br>
<br>
Frank<br>
<br>
Al 21/05/10 18:00, En/na <a class="moz-txt-link-abbreviated" href="mailto:users-request@openvz.org">users-request@openvz.org</a> ha escrit:<br>
<blockquote cite="mid:201005211600.o4LG0Ceb009847@vzorg.swsoft.net"
type="cite">
<pre wrap=""><div class="moz-txt-sig">Date: Fri, 21 May 2010 17:56:52 +0200
From: Benoit Branciard <a moz-do-not-send="true"
class="moz-txt-link-rfc2396E"
href="mailto:Benoit.Branciard@univ-paris1.fr"><Benoit.Branciard@univ-paris1.fr></a>
Subject: Re: [Users] Re: network problems: eth0: received packet with
own SOLVED and POSSIBLE BUG <b class="moz-txt-star"><span
class="moz-txt-tag">*</span>WARNING<span class="moz-txt-tag">*</span></b>)
To: <a moz-do-not-send="true" class="moz-txt-link-abbreviated"
href="mailto:users@openvz.org">users@openvz.org</a>
Message-ID: <a moz-do-not-send="true" class="moz-txt-link-rfc2396E"
href="mailto:4BF6AD44.8030907@univ-paris1.fr"><4BF6AD44.8030907@univ-paris1.fr></a>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
frank a écrit :
</div></pre>
<blockquote type="cite" style="color: rgb(0, 0, 0);">
<pre wrap=""><span class="moz-txt-citetags">> </span>Hi,
<span class="moz-txt-citetags">> </span>after a lot of tests I looked at a Xen machine, which also use ethernet
<span class="moz-txt-citetags">> </span>bridges and veths, and I noticed that it always use MAC
<span class="moz-txt-citetags">> </span>address FE:FF:FF:FF:FF:FF for the veths. I have test it on VE's
<span class="moz-txt-citetags">> </span>and...voila! No more mess with the MACs! Now the MAC of the ethernet
<span class="moz-txt-citetags">> </span>bridge is always the same, the host main ethernet interface one.
<span class="moz-txt-citetags">> </span>
<span class="moz-txt-citetags">> </span>I don't know the exact reason for this, but I'm sure it is an important
<span class="moz-txt-citetags">> </span>BUG for all who use veths with ethernet bridge.
<span class="moz-txt-citetags">> </span>Please, solve it as soon as you can.
<span class="moz-txt-citetags">> </span>Thanks.
<span class="moz-txt-citetags">> </span>
</pre>
</blockquote>
<pre wrap="">This is a feature (I don't remember where I read it, but it's documented
somewhere): under Linux, a bridge's MAC address takes the numerically
<b class="moz-txt-star"><span class="moz-txt-tag">*</span>lowest<span
class="moz-txt-tag">*</span></b> value amongst those of the bridged interfaces which belong to it.
FE:FF:FF:FF:FF:FF is the higher possible locally-defined unicast MAC
address value and therefore is the least prone to interfere with the
bridge's MAC (unless there are no other MAC addresses into the bridge).
So the bridge-side of veths (not the VE-side, which will be visible on
the network and should remain unique) SHOULD ALWAYS be FE:FF:FF:FF:FF:FF
for convenience, or at least be chosen higher than any other MACs
present on the system (FE:xx:xx:xx:xx range is a good choice).
To my knowledge, mention about this is extremely sparse in OpenVZ's
documentation, and <b class="moz-txt-star"><span class="moz-txt-tag">*</span>not<span
class="moz-txt-tag">*</span></b> taken into account by vzctl when automatically
generating MAC addresses with "vzctl --netif-add" with blank MAC
parameters. This may be considered as a bug.
<div class="moz-txt-sig">--
Benoit BRANCIARD
Pôle Infrastructures
Centre de ressources informatiques et du réseau (CRIR)
Université Paris 1 Panthéon-Sorbonne
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://crir.univ-paris1.fr">http://crir.univ-paris1.fr</a>
Tel. 01 44 07 89 68
</div></pre>
</blockquote>
<br>
<br />--
<br />Aquest missatge ha estat analitzat per
<a href="http://www.mailscanner.info/"><b>MailScanner</b></a>
<br />a la cerca de virus i d'altres continguts perillosos,
<br />i es considera que está net.
</body>
</html>