From mboxrd@z Thu Jan  1 00:00:00 1970
From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=
	<u.kleine-koenig@pengutronix.de>
Subject: Re: sysctls below net.ipv[46].conf.all not working as expected
Date: Thu, 30 Dec 2010 21:20:36 +0100
Message-ID: <20101230202036.GD14221@pengutronix.de>
References: <20101229160607.GH14221@pengutronix.de>
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Cc: Marco d'Itri <md@linux.it>
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Hello again,

On Wed, Dec 29, 2010 at 05:06:07PM +0100, Uwe Kleine-K=F6nig wrote:
> I did the following:
>=20
> 	cassiopeia:~# sysctl net.ipv6.conf.all.use_tempaddr
> 	net.ipv6.conf.all.use_tempaddr =3D 0
>=20
> 	cassiopeia:~# sysctl net.ipv6.conf.eth0.use_tempaddr
> 	net.ipv6.conf.eth0.use_tempaddr =3D 0
>=20
> 	cassiopeia:~# sysctl -w net.ipv6.conf.all.use_tempaddr=3D1
> 	net.ipv6.conf.all.use_tempaddr =3D 1
>=20
> 	cassiopeia:~# sysctl net.ipv6.conf.all.use_tempaddr
> 	net.ipv6.conf.all.use_tempaddr =3D 1
>=20
> 	cassiopeia:~# sysctl net.ipv6.conf.eth0.use_tempaddr
> 	net.ipv6.conf.eth0.use_tempaddr =3D 0
>=20
> Here I would have expected that eth0's use_tempaddr is 1, too.  The
> problem is not that this entry isn't writeable:
>=20
> 	cassiopeia:~# sysctl -w net.ipv6.conf.eth0.use_tempaddr=3D1
> 	net.ipv6.conf.eth0.use_tempaddr =3D 1
>=20
> 	cassiopeia:~# sysctl net.ipv6.conf.eth0.use_tempaddr
> 	net.ipv6.conf.eth0.use_tempaddr =3D 1
>=20
> I got the same results when using net.ipv4.conf.all.rp_filter (and
> net.ipv4.conf.eth0.rp_filter resp.)
>=20
> Is this a bug or just my failure to see how conf/all works?
I put the following in my /etc/sysctl.conf:

	net.ipv6.conf.default.use_tempaddr =3D 1
	net.ipv6.conf.all.use_tempaddr =3D 1
	net.ipv6.conf.eth0.use_tempaddr =3D 1

and after a reboot eth0 got a temporary dynamic address, eth1 did not.
So it doesn't seem to be as guessed by someone on #debian-kernel that
the setting works but isn't propagated back to the sysctl of the
interface.

This makes me wonder how useful the lines

	net.ipv4.conf.default.rp_filter =3D 1
	net.ipv4.conf.all.rp_filter =3D 1

(suggested by the Debian package netbase) are.

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-K=F6nig        =
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Industrial Linux Solutions                 | http://www.pengutronix.de/=
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