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Re: [DNSOP] My "toxic" remark at the mic today

Tony Finch <dot@dotat.at> Thu, 05 November 2015 11:54 UTC

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Date: Thu, 05 Nov 2015 11:54:39 +0000
From: Tony Finch <dot@dotat.at>
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Subject: Re: [DNSOP] My "toxic" remark at the mic today
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John Levine <johnl@taugh.com> wrote:
>
> On the other hand, there's at least one delegated TLD that has a DNAME
> at the apex.  It's been around for several years, it seems to work OK.

$ dig axfr . |
  sed -E '/^([a-z0-9-]+)[.][ 	].*/!d;s//\1/' |
  sort -u | while read d; do
  dig +noall +answer DNAME $d.; done
xn--kprw13d.            86400   IN      DNAME   xn--kpry57d.
xn--mgba3a4f16a.        1440    IN      DNAME   xn--mgba3a4f16a.ir.

Scanning the root zone is getting slow without concurrency :-) The above
takes 3 minutes from a cold cache whereas adns takes 12 seconds (though
you have to hack round its lack of support for DNAME).

$ dig axfr . |
  sed -E '/^([a-z0-9-]+)[.][ 	].*/!d;s//sladjfhkjlasdhf.\1./' |
  sort -u | adnshost --asynch --pipe --type cname | grep CNAME
sladjfhkjlasdhf.xn--kprw13d CNAME sladjfhkjlasdhf.xn--kpry57d
sladjfhkjlasdhf.xn--mgba3a4f16a CNAME sladjfhkjlasdhf.xn--mgba3a4f16a.ir

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
Trafalgar: Southwesterly 4 or 5, increasing 6 or 7 in northwest. Moderate or
rough. Showers. Good, occasionally moderate.

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