Subject: why NS records in answers?

From: "D. J. Bernstein" <[email-masked]>
Date: 30 Nov 1999 23:58:14 -0000

[email-masked] writes:
> Because you don't get the load spread over the correct servers
> if you don't.

I don't understand. Are you saying that your parent servers have only
some of your NS records? You're sending the complete NS list with your
answers to override the incomplete list in the client's cache?

In that situation, your load is still skewed by all the clients that are
contacting you for the first time, because they're using the incomplete
list. Right?

Why not give your parent servers the complete NS list? Is it too much
work to notify the parent of NS changes? What if the parent servers
automatically check with your servers for NS changes?

---Dan

---

From: [email-masked]
Date: Wed, 01 Dec 1999 19:13:47 +1100

> answers to override the incomplete list in the client's cache?

	No. See below.
> automatically check with your servers for NS changes?

	Take the following two zones with the delegations as below.

	example.com NS ns1.example.com
	example.com NS ns2.example.com

	sub.example.com NS ns1.example.com
	sub.example.com NS ns2.example.com
	sub.example.com NS ns1.sub.example.com
	sub.example.com NS ns2.sub.example.com

	Unless you return the NS RRset for queries in sub.example.com
	ns1.sub.example.com and ns2.sub.example.com will not be queried.

	This is a very common setup in companies.

	Yes the is some skew, but not as much as if you didn't return the
	RRset.

	Mark
--
Mark Andrews, Internet Engines Inc. / Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]