From: Stephen Hemminger <shemminger@vyatta.com>
To: Marc Haber <mh+netdev@zugschlus.de>
Cc: netdev@vger.kernel.org
Subject: Re: Bridge stays down until a port is added
Date: Mon, 26 Sep 2011 08:47:43 -0700 [thread overview]
Message-ID: <20110926084743.35cb2ccc@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <20110925082504.GA32712@torres.zugschlus.de>
The root of this whole problem is really that IPv6 reports addresses
in a tentative state to applications that can not be passed to the bind() system call.
For most cases, this problem never happens because the tentative addresses are
resolved by Duplicate Address Detection before the application starts. But
I have seen (and fixed) this happen before this whole discussion started.
1. The problem is not unique to bridges. It happens with bridge, macvtap,
even on wireless networks where the device is available but carrier is
not asserted.
2. Any change to what the kernel does (like not reporting tentative addresses)
would break applications even worse.
3. When the bridge was always reporting carrier, it was in effect breaking
IPv6 Duplicate Address Detection. And that is bad.
next prev parent reply other threads:[~2011-09-26 15:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-11 7:06 Bridge stays down until a port is added Marc Haber
2011-08-11 15:17 ` Stephen Hemminger
2011-08-11 20:54 ` Marc Haber
2011-08-11 22:41 ` Stephen Hemminger
2011-08-12 12:22 ` Sven-Haegar Koch
2011-08-20 9:47 ` Marc Haber
2011-08-20 16:30 ` Stephen Hemminger
2011-08-21 12:13 ` Marc Haber
2011-08-22 15:57 ` Stephen Hemminger
2011-09-17 20:42 ` Marc Haber
2011-09-20 20:20 ` Dan Williams
2011-09-25 8:25 ` Marc Haber
2011-09-26 15:47 ` Stephen Hemminger [this message]
2011-09-26 20:02 ` Nicolas de Pesloüan
2011-09-26 20:05 ` Stephen Hemminger
2011-09-26 20:56 ` Ben Hutchings
2011-09-26 22:12 ` Nicolas de Pesloüan
2011-09-26 22:42 ` Stephen Hemminger
2011-09-27 0:28 ` Sven-Haegar Koch
2011-09-27 0:43 ` Stephen Hemminger
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