[geeks] a little advice about DNS and naming conventions

Greg A. Woods woods at weird.com
Thu Mar 14 13:47:56 CST 2002


[ On Friday, March 15, 2002 at 00:05:01 (+1100), Scott Howard wrote: ]
> Subject: Re: [geeks] ADMINISTRIVIA: Changes to mail delivery policies
>
> Hint: A "Secondary Nameserver" is a server which is not a "Primary
> Nameserver". ie, one which gets it's zonefile via a zone transfer rather
> than from a local file.

Well ever since I've been doing BIND development back in the BIND-4 days
we've called the things you describe "master" and "slave" servers.

However from the world`s point of view they're all identical -- they all
answer authoritatively for the zones loaded in their caches, and the one
that will be queried will essentially be randomn due to the distributed
nature of the DNS, the fact that different forwarding nameservers will
have different TTLs depending on when they queried the parent zones, and
the fact that NS records are supposed to always be returned in
round-robin fashion.

There is no such thing as a "secondary" nameserver.  Those who think so
are confused by the use of the word "primary" in the original BIND boot
file to describe a zone file loaded by a master nameserver.

Strictly speaking the "primary" nameserver is the one declared in the
first field of the SOA RR for the zone, but it need not be the one that
loaded the original master zone file.  So far as I know there's no
software in common use that pays any special attention to the "primary"
nameserver.  The only tools I know of that do so are special testing
tools, including ones I wrote.

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
Planix, Inc. <woods at planix.com>; VE3TCP; Secrets of the Weird <woods at weird.com>



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