[dns-operations] EDNS with IPv4 and IPv6 (DNSSEC or large answers)

Tony Finch dot at dotat.at
Mon Sep 15 11:31:32 UTC 2014

Roland Dobbins <rdobbins at arbor.net> wrote:
> On Sep 15, 2014, at 5:52 PM, Tony Finch <dot at dotat.at> wrote:
> > That is, you need to limit the size of response that you send (max-udp-size in BIND terms).
> Do you recommend that it be lowered to 1280 or thereabouts for IPv6?

Not enough data, sorry. In practice the ethernet MTU minus some slop for
headers and tunnels seems to be enough. Our main experience of DNS
resolution problems has been with Windows shops (the symptom is delayed
mail from Exchange servers) and I have never been able to get in touch
with a tech who cares enough about the problem to provide details or help
fix it.

f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/
Trafalgar: Cyclonic in northwest, otherwise mainly northerly or northwesterly
5 or 6. Slight or moderate. Showers in northwest. Good.

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