Re: [DNSOP] Terminology question: split DNS

"Darcy Kevin (FCA)" <> Mon, 19 March 2018 19:26 UTC

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From: "Darcy Kevin (FCA)" <>
To: dnsop <>
Thread-Topic: [DNSOP] Terminology question: split DNS
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Date: Mon, 19 Mar 2018 19:26:42 +0000
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Subject: Re: [DNSOP] Terminology question: split DNS
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The trouble with "split horizon" is that it is a term of inter-network routing of much older and more-established provenance, and thus to use it for DNS can be viewed as a usurpation, and ultimately, confusing. (I know Cricket had the same observation, circa 2000).

I occasionally use "schizophrenic DNS" when I want to disparage the practice, but I realize that is both a) inaccurate, from a clinical standpoint, and b) politically incorrect, in some circles.

How about just "disjoint DNS" or "non-synchronized DNS"? Or, to hijack the Perl motto, TMTOWTRI (There's More Than One Way To Resolve It :-)

														- Kevin

-----Original Message-----
From: DNSOP [] On Behalf Of Paul Vixie
Sent: Monday, March 19, 2018 1:55 PM
To: Paul Hoffman <>
Cc: dnsop <>
Subject: Re: [DNSOP] Terminology question: split DNS

Paul Hoffman wrote:
> Some folks had reservations about the current definition of "split
> DNS": "Where a corporate network serves up partly or completely 
> different DNS inside and outside its firewall. There are many possible 
> variants on this; the basic point is that the correspondence between a 
> given FQDN (fully qualified domain name) and a given IPv4 address is 
> no longer universal and stable over long periods." (Quoted from <xref 
> target="RFC2775"/>, Section 3.8)
> What would the WG like for this definition?

my only qualm is that A and AAAA RR's are not the only things that are usually not the same when DNS is split in this way. MX, NS, SRV, and likely a dozen others, and DNSSEC signatures and keys, can also differ.

it should be called split-horizon DNS not split-DNS, to highlight the fact that it's the same zone name in an entirely separate DNS namespace.

P Vixie

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