nslookup Got recursion not available from... trying next server

Niall O'Reilly Niall.oReilly at ucd.ie
Wed Jan 5 23:24:57 UTC 2011

On 05/01/11 21:36, vr wrote:
> I'm having a query problem and hope I'm at the right mailing list...

	Formally, probably not, since what you describe isn't a BIND
	issue.  That said, the people on this list are likely among
	those who can best give you helpful advice.

> I get a "recursion not available" message intermittently when using
> nslookup.

	The short answer is, "Yes indeed: that's how DNS works."
	A longer answer follows below.

	I should mention first that I have no experience using
	'nslookup'.  I understand that it has a reputation for masking
	the information actually needed for troubleshooting by trying
	too hard to be "helpful".  I don't actually know whether this
	reputation is deserved.

	I suggest you use 'dig' instead.  I count myself lucky that
	this was the first DNS troubleshooting tool I was introduced to
	by our then "Internet expert" nearly 20 years ago. [Thanks,
	Mike!]  I've never felt the need to use another, and probably
	haven't even yet discovered all of its features.

> The message will appear on the first query, presumably to
> un-cached IP/hostname and subsequent queries to the same IP/hostname
> will succeed without the message.

	It is normal, and actually good practice, for any authoritative
	name server (the master or slave for a given zone) to be
	configured to refuse to provide recursive name service.
	I guess that 'nslookup' is by default making a recursive query,
	happens to send that query to an authoritative server, receives
	a response in which the "recursion not available" flag is set,
	and duly displays a message which appears at first sight to be

	As it happens, 'dig' also makes a recursive query by default,
	although it's easy to tell it not to.  Besides, 'dig' just
	shows the flags; it doesn't convert them into potentially
	disturbing messages.

	I hope this helps.

	Best regards,

	Niall O'Reilly
	University College Dublin IT Services

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