EDNS probing

[Tony Finch]

I am looking at the new EDNS probing code to see if I can reduce the
interop problems that we have been finding (RT #36330 and #36622 for those
who can see).

What is the interaction between the old fctx->triededns* lists and the new
dns_adb_udpsize code? I'm a bit puzzled that the old three-way logic is
still there despite the new multi-level probing - I would have expected
the new code to take over the EDNS512 vs EDNS4096 decision.

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/
Irish Sea: East or northeast 3 or 4, occasionally 5 at first. Smooth or
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