All of lore.kernel.org
 help / color / mirror / Atom feed
From: Flavio Leitner <fbl@redhat.com>
To: netdev <netdev@vger.kernel.org>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Subject: restoring IP multicast addresses when restarting the interface.
Date: Fri, 20 Apr 2012 21:25:33 -0300	[thread overview]
Message-ID: <20120420212533.78903e3a@asterix.rh> (raw)


Hello folks,

I was told that ntp in multicast mode was not working if you
restart the interface (ifdown <iface> ; ifup <iface) on an
older kernel.

It seemed obvious to me, but when I tried to reproduce this
upstream (last kernel of today), I noticed that the kernel
does restore the previous added multicast addresses. Therefore,
there is no issues.

I found that this is due to mainly this commit below which
doesn't remove idev when the addresses are deleted.

commit 6363097cc4d182f93788131b5d8f72aa91d950a0
Author: Herbert Xu <herbert@gondor.apana.org.au>
Date:   Thu Jun 7 18:35:38 2007 -0700

    [IPV4]: Do not remove idev when addresses are cleared
    
    Now that we create idev before addresses are added, it no longer makes
    sense to remove them when addresses are all deleted.
    
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Signed-off-by: David S. Miller <davem@davemloft.net>


Although the new behavior seems nice and save some user space
work, I think it was unintentional and likely to be a bug.

What you guys think?

thanks,
fbl

             reply	other threads:[~2012-04-21  0:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-21  0:25 Flavio Leitner [this message]
2012-04-23 12:14 ` restoring IP multicast addresses when restarting the interface Herbert Xu
2012-04-24 18:30   ` Flavio Leitner
2012-04-24 21:00     ` David Miller
2012-04-24 21:28       ` David Stevens
2012-04-24 22:19         ` Flavio Leitner

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=20120420212533.78903e3a@asterix.rh \
    --to=fbl@redhat.com \
    --cc=herbert@gondor.hengli.com.au \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.