Split-Horizon DNS Configuration in Enterprise Networks
draft-reddy-add-enterprise-split-dns-00

Document Type Active Internet-Draft (individual)
Authors Tirumaleswar Reddy.K  , Dan Wing 
Last updated 2021-02-20
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ADD                                                             T. Reddy
Internet-Draft                                                    McAfee
Intended status: Standards Track                                 D. Wing
Expires: August 24, 2021                                          Citrix
                                                       February 20, 2021

         Split-Horizon DNS Configuration in Enterprise Networks
                draft-reddy-add-enterprise-split-dns-00

Abstract

   When split-horizon DNS is deployed by an enterprise, certain
   enterprise domains are only resolvable by querying the network-
   provided DNS server.  DNS clients which use DNS servers not provided
   by the network need to route those DNS domain queries to the network-
   provided DNS server.  This document informs DNS clients of split-
   horizon DNS, their DNS domains, and is compatible with encrypted DNS.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 24, 2021.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of

Reddy & Wing             Expires August 24, 2021                [Page 1]
Internet-Draft       Split-Horizon DNS Configuration       February 2021

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Scope of the Document . . . . . . . . . . . . . . . . . . . .   4
   4.  Split DNS . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  PvD dnsZones  . . . . . . . . . . . . . . . . . . . . . . . .   6
   6.  PvD SplitDNSAllowed Key . . . . . . . . . . . . . . . . . . .   7
   7.  An Example  . . . . . . . . . . . . . . . . . . . . . . . . .   7
   8.  Roaming Enterprise Users  . . . . . . . . . . . . . . . . . .   8
   9.  Upstream Encryption . . . . . . . . . . . . . . . . . . . . .   8
   10. Security Considerations . . . . . . . . . . . . . . . . . . .   9
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   12. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     13.1.  Normative References . . . . . . . . . . . . . . . . . .   9
     13.2.  Informative References . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   Historically, an endpoint would utilize network-provided DNS servers
   upon joining a network (e.g., DHCP OFFER, IPv6 Router Advertisement).
   While it has long been possible to configure endpoints to ignore the
   network's suggestions and use a (public) DNS server on the Internet,
   this was seldom used because some networks block UDP/53 (in order to
   enforce their own DNS policies).  With the advent of DoT and DoH,
   such network blocking is more difficult, but the endpoint is unable
   to (properly) resolve split-horizon DNS domains which must query the
   network-provided DNS server.

   [RFC7626] discusses DNS privacy considerations in both "on the wire"
   (Section 2.4 of [RFC7626]) and "in the server" (Section 2.5 of
   [RFC7626]) contexts.  Also, there has been an increase in the
   availability of "public resolvers" [RFC8499] which DNS clients may be
   pre-configured to use instead of the default network resolver for a
   variety of reasons (e.g., offer a good reachability, support an
   encrypted transport, provide a claimed privacy policy, (lack of)
   filtering).

   If public encrypted DNS servers (e.g., DNS-over-TLS (DoT) [RFC7858]
   or DNS-over-HTTPS (DoH) [RFC8484]) are used instead of using local
   DNS servers, it can adversely impact Enterprise network-based
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