[dns-operations] Reverse Lookup speedup

Mark Andrews Mark_Andrews at isc.org
Thu Aug 2 08:00:22 UTC 2007

> > Slaving in-addr.arpa, like FreeBSD does, does not save you a lot of
> > lookups. Unlike forward requests, where there are a lot of typos which
> > can be catched only by the root, reverse lookups always have an
> > existing "TLD" and therefore I suspect that the cache is sufficient.
> most of the typo's are before the tld.  slaving every tld on every
> recursive server everywhere on the internet seems contraindicated.

	I can remember when it made a lot sence to keep a local
	copy of in-addr.arpa.  Not for speed but just to keep
	in country lookups working.  The speed up was a secondary

	Luckly there is enough cable paths that one of the roots
	is always reachable these days.  It would however be nice
	if my ISP decided to peer with at least one or preferably
	both of the local root instances.

	The closest, reachable, root is 187 ms away (rtt) and I
	know there are ones sub 30 ms way if my ISP would only peer.


Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org

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