Test your connectivity for World IPv6 Day
nanog at 85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org
Tue Jun 7 14:29:20 CEST 2011
On Tue, 7 Jun 2011 12:30:08 +0200
Rémi Després <remi.despres at free.fr> wrote:
> Le 6 juin 2011 à 21:41, Daniel Roesen a écrit :
> > On Mon, Jun 06, 2011 at 05:58:43PM +0200, Rémi Després wrote:
> >> Unless there are good reasons to know that a longer PMTU applies to all
> >> their connections, all servers SHOULD send IPv6 packets to off-link
> >> destinations with 1280 octets as default PMTU.
> > So you advocate making 1280 effectively the maximum MTU, not the minimum?
> The "default" MTU, not the "maximum".
> If some PMTUD permits to detect that a larger PMTU is possible on a specific path, it can then be used.
Conventional PMTUD only works downwards, so if you start at a
default MTU 1280, you'll never discover a larger PMTU than 1280. MSS
also works to constrain that, as it tells the other end the maximum
segment size to send.
> Also, on-link connections can use the link MTU.
> > I'm with Fred here. Fix broken paths, not work around the problems.
> > Best regards,
> > Daniel
> > --
> > CLUE-RIPE -- Jabber: dr at cluenet.de -- dr at IRCnet -- PGP: 0xA85C8AA0
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