Subject: RE: (ngtrans) Re: 6to4/isatap MTU

From: "Christian Huitema" <[email-masked]>
Date: Wed, 4 Sep 2002 10:15:42 -0700

> Christian Huitema wrote:
> > Once burned, twice shy. I know that we can do clever tricks, such as
the
> > one I described, in order to get performance benefits. The "burned"
part
> > comes from the experience that clever tricks often backfire: the
sender
> > assumes that the clever trick is implemented, the receiver does not
> > implement it, or implements it wrongly, and you get a black hole.
> 
> This is why we develop standards.

Problem is, we are not developing a new standard -- we are updating an
already published one, for which there are many existing
implementations. You cannot expect that all these existing
implementations will be updated to the new RFC -- certainly not
overnight.

> > I am not sure that an attempt to use large MTU for tunnels would
> > actually result in better overall performance.
> 
> Are you talking about tunnels generically here?

Self configured tunnels, as used by 6to4 or ISATAP. Presumably, we could
implement actual IPv4 PMTU discovery for a configured tunnel.

-- Christian Huitema

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From: "Fred L. Templin" <[email-masked]>
Date: Wed, 04 Sep 2002 11:50:11 -0700

> implementations will be updated to the new RFC -- certainly not

I assume here you are talking about RFC 2893(bis)? Other documents
which have not yet been accepted as standards (e.g., isatap) can
certainly go "off-plan" and and specify their own PMTUD mechanisms,
correct?

Fred
[email-masked]

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From: "Fred L. Templin" <[email-masked]>
Date: Wed, 04 Sep 2002 13:38:29 -0700

Fred
[email-masked]