From: Stephen Hemminger <shemminger@vyatta.com>
To: Marc Haber <mh+netdev@zugschlus.de>
Cc: netdev@vger.kernel.org, Sven-Haegar Koch <haegar@sdinet.de>
Subject: Re: Bridge stays down until a port is added
Date: Mon, 22 Aug 2011 08:57:30 -0700 [thread overview]
Message-ID: <20110822085730.69d56034@nehalam.ftrdhcpuser.net> (raw)
In-Reply-To: <20110821121305.GA22232@torres.zugschlus.de>
On Sun, 21 Aug 2011 14:13:05 +0200
Marc Haber <mh+netdev@zugschlus.de> wrote:
> On Sat, Aug 20, 2011 at 09:30:59AM -0700, Stephen Hemminger wrote:
> > The problem is that IPv6 Duplicate Address Detection needs to
> > work. This is not a simple problem. If the bridge asserted
> > carrier with no ports then:
> >
> > 1. IPv6 address assigned and IPv6 decides it is okay.
> > 2. Port added later
> > 3. Another system has the same address.
> > *broke*
>
> Same situation when a system-to-system-link is added after bringing up
> an interface. I agree that the issue is not an issue if a real switch
> is being used.
>
> > If you want to avoid DAD, then you can configure disable DAD
> > by setting /proc/sys/net/ipv6/conf/br0/accept_dad to 0
>
> I'd like to avoid that.
>
> 2001:db8::1
>
> Would it acceptable (and clean!) to have:
>
> eth0: 2001:db8:1::100/64 default gw to the internet is 2001:db8:1::1
> lo: 127.0.0.1/8, ::1/128, 2001:db8:2::100/64
> br0: 2001:db8:2::1/64 (being default gw for the VMs connected to br0,
> routing 2001:db8:2::/64 to the Internet)
>
> Note 2001:db8:2::/64 being used both on lo and br0, with 2001:db8:2::100 meant
> to be reachable from the Internet even if no VM is already up. my
> hostname will be A-Recorded to 2001:db8:2::100 with proper reverse
> DNS. The background for doing so is that I cannot control the reverse
> DNS for the IP addresses inside 200a:db8:1::/64 in a lot of my setups
> (for example, if my IPv6 comes in via Sixxs).
>
No, DAD config is per interface and addrconf doesn't know anything
about your topology.
next prev parent reply other threads:[~2011-08-22 15:57 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 [this message]
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
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110822085730.69d56034@nehalam.ftrdhcpuser.net \
--to=shemminger@vyatta.com \
--cc=haegar@sdinet.de \
--cc=mh+netdev@zugschlus.de \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).