From: Andrew Lunn <andrew@lunn•ch>
To: David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org
Subject: Re: [net-next RFC] net: ipv4: Send IGMP messages from highest scoped address
Date: Tue, 18 Aug 2015 22:31:44 +0200 [thread overview]
Message-ID: <20150818203144.GL4381@lunn.ch> (raw)
In-Reply-To: <20150818.120110.838819870003861953.davem@davemloft.net>
On Tue, Aug 18, 2015 at 12:01:10PM -0700, David Miller wrote:
> From: Andrew Lunn <andrew@lunn•ch>
> Date: Tue, 18 Aug 2015 15:36:41 +0200
>
> > We currently take the first address from the interface which is scope
> > link or higher.
> >
> > Historically, the global scope address would of been used, but my
> > previous fix, which stopped it taking a global scope address from a
> > different interface altogether under some conditions, changed this
> > behaviour.
> >
> > The first address from the interface, then broke one of my use
> > case. The querier is only in one of the subnets on this interface, and
> > using an address from the global scope address range. It then drops
> > the membership reports when they are sent from the first address on
> > the interface. This is why i want to restore the previous behaviour,
> > take the global scope address from this interface.
> >
> > The patch works for me and is restoring previous behaviour, but is
> > that sufficient to make it correct?
>
> Preferring link-scope addresses make so much more sense for me.
>
> The querier is on the local network, and he can do things like the
> validity check on the subnet of the source address to try and avoid
> forged IGMP responses.
>
> So if anything I'd be advising you to change the code to prefer
> link local addresses on the interface and keep avoiding global
> addresses, as it is the only correct source address selection
> scheme I can think of for IGMPs.
Hi David
O.K, thanks for the discussion, and this patch can be ignored.
Andrew
prev parent reply other threads:[~2015-08-18 20:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-17 16:09 [net-next RFC] net: ipv4: Send IGMP messages from highest scoped address Andrew Lunn
2015-08-18 4:31 ` David Miller
2015-08-18 13:36 ` Andrew Lunn
2015-08-18 19:01 ` David Miller
2015-08-18 20:31 ` Andrew Lunn [this message]
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=20150818203144.GL4381@lunn.ch \
--to=andrew@lunn$(echo .)ch \
--cc=davem@davemloft$(echo .)net \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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