Re: [Int-area] I-D Action: draft-ietf-intarea-tunnels-05.txt

Joe Touch <touch@isi.edu> Wed, 03 May 2017 22:05 UTC

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To: "Templin, Fred L" <Fred.L.Templin@boeing.com>
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From: Joe Touch <touch@isi.edu>
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Date: Wed, 3 May 2017 15:04:12 -0700
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Subject: Re: [Int-area] I-D Action: draft-ietf-intarea-tunnels-05.txt
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Winding down to the last part:

(I agree that encryption or mimicry is useful only when it works, but
not much more can be said than that)


On 5/3/2017 2:59 PM, Templin, Fred L wrote:
> The problem is that if there are N paths in the multipath the ingress has
> no way of knowing that it has probed all N of them. And, if a transit
> packet arrives that would be tunneled over a path that has not been
> probed, it could black hole if the MTU is too small.

That's correct - PLPMTUD can fail at any time if the PMTU changes and
becomes smaller (for any reason, including link reconfiguration, path
changes, multipath selection).

That's why it keeps retrying. Again, this isn't new or unique to tunnels.

Joe