Movatterモバイル変換

Network Working Group                        Internet Architecture BoardRequest for Comments: 1401                           Lyman Chapin, Chair                                                            January 1993Correspondence between the IAB and DISA on the use ofDNS throughout the InternetStatus of this Memo   This memo provides information for the Internet community.  It does   not specify an Internet standard.  Distribution of this memo is   unlimited.Abstract   This memo reproduces three letters exchanged between the Internet   Activities Board (IAB) and the Defense Information Systems Agency   (DISA) regarding the importance of using the Domain Name System (DNS)   throughout the Internet, and phasing out the use of older host name   to address tables, such as "hosts.txt".IAB                                                             [Page 1]

RFC 1401            IAB & DISA Correspondence on DNS        January 19931.  Letter from the IAB to DISA                                                   30 March, 1992   To: Members of the Federal Networking Council,       Members of the Federal Networking Advisory Council,       Colonel Ken Thomas, Chairman,           DoD Protocol Standards Steering Group, DISA/Center for           Standards   CC: C. J. Pasquariello, Associate Director, Center for Standards,       LCDR, David Chappell, Executive Secretary,           PSSG, DISA/Center for Standards       Eduardo Schonborn, Dep Director/DDN PMO   As the IAB, together with others in the Internet Engineering and   Research Task Forces, contemplates the challenges inherent in dealing   with an exponentially expanding Internet, the critical need for   widespread adoption of a uniform Domain Name service is very   apparent.   The attached memorandum is offered by the Internet Activities Board   for your consideration regarding technical policy concerning domain   naming in the US portion of the Internet.  The proposed technical   policy is recommended world-wide and will be offered as an RFC for   that purpose.  Adoption of such a policy would, we believe, much   enhance the operational efficiency of the existing world-wide   Internet backbone and major networks dependent upon it, including the   DDN Milnet.   Your consideration of this policy question is urged in the strongest   possible terms.  We would much appreciate hearing the views of the   Protocol Standards Steering Group by April 20, 1992.   Regards,   A. Lyman Chapin   Chairman, Internet Activities BoardIAB                                                             [Page 2]

RFC 1401            IAB & DISA Correspondence on DNS        January 1993Attachment              The Domain Name System is an Internet Necessity                         Internet Activities Board                               February 1992   Over the last several years, the Internet has evolved in size so   extensively that it has become infeasible to provide directory   services through a database maintained at a single, central   repository.  Both the size and the dynamics of the required data make   such an approach impractical.  Recognizing this problem several years   ago [1], the Internet community has adopted the Domain Name System   [2-5] as the principal means of achieving host name to IP address   mappings.  During this time, almost the entire Internet has converted   from the use of the static name-to-address mapping tables thus far   centrally maintained at the DDN Network Information Center, to the   use of the more dynamic, up-to-date address mapping provided by DNS   mechanism.   There are still large fractions of the Internet community which rely   on the use of a centrally-maintained file ("hosts.txt") to accomplish   this mapping function.  The MILNET community appears to have   substantial pockets of dependence on table-driven mappings, for   example.  Although a plan for achieving a MILNET transition to use of   the Domain Name System was worked out in 1987, the transition is   incomplete and, as a result, naming services (i.e., host name lookups   on the MILNET) are many times still provided via static tables rather   than the distributed, and far more accurate, Domain Name System.   Ironically, most of the commercial, off-the-shelf software for TCP/IP   supports the user of the Domain Name System, so a policy of uniform   support and application of DNS would go a long way toward improving   the Defense Department data communication infrastructure, insofar as   it is dependent on TCP/IP to interconnect hosts on LANs and WANs.   The use of different means for name-to-address mappings by different   parties in the network community leads to unsynchronized and   inconsistent databases, which inevitably result in reachability   failures by users attempting to connect to network resources.   Moreover, the special facilities of the Domain Name System, such as   the MX (Mail eXchange) record, make it possible to include systems   not directly on the Internet into the universe of addressable   parties.  MX records also allow a network administrator to prioritize   a list of alternative e-mail relays in case the final destination is   not reachable.  Systems which do not support MX records, but rather   still depend on the "hosts.txt" information, pose a serious obstacle   to network connectivity, as well as to the operation and managementIAB                                                             [Page 3]

RFC 1401            IAB & DISA Correspondence on DNS        January 1993   of the highly connected Internet.   Non-DNS systems on the Internet will eventually be confronted with   the need to decide whether they want to continue as a part of the   larger Internet community, or remain a rather small, non-conforming   subset.  Should they choose not to conform to the otherwise accepted   Domain Name System, they will have to accept the ramifications of   this decision.  In particular, they will have to accept that the rest   of the community may, indeed has already started to, essentially   ignore those static files which reflect the principal non-DNS naming   service.  The larger community has evolved so extensively beyond   these configurations, that these files are not only obsolete as a   technology, but also incomplete and often inaccurate in the present   implementation.  Upon connecting a new host to the Internet, the   great majority of the Internet community no longer considers the   registration of host name/address updates to the NIC database a   necessity, and rather focuses on updating the Domain name System.   Therefore, today's NIC database, and the "hosts.txt" file generated   from it, largely reflects only the non-DNS community, a tiny subset   of the hundreds of thousands of entities configured into the Internet   name space via the DNS.   If the non-DNS users maintain a requirement for the use of static   mapping tables, at least some mechanism should exist to augment the   NIC data sets with additional information represented by the Domain   Name System.  These more comprehensive tables, accompanied by a   method to guarantee synchronization with the DNS, would significantly   improve the accuracy of the information which non-DNS users apply to   map between names and addresses.  However, this solution will not   address the need for support of the richer DNS functionality by the   NIC's system.  At a minimum, the incorporation of MX information into   the NIC database is imperative for compatibility between the   "hosts.txt" file and the DNS.  Network subcommunities which choose to   maintain a separate and incompatible mapping system will have a   partitioning effect on the subcommunities themselves, but also a   detrimental impact on overall Internet operations.  Both end-users   and system and network administrators will inevitably find themselves   devoting considerable attention to tracing inconsistency problems   arising from the discrepancy in mapping methods.   The Internet Activities Board, recognizing the need for universal   interoperability and consistent naming mechanisms, and benefitting   from several years of experience with the Domain Name System, is   advocating a policy that all connected components of the Internet   community should adopt the DNS, and urges parties having policy-   setting authority to adopt the same position and undertake to set   deadlines for conversion to uniform use of DNS.IAB                                                             [Page 4]

RFC 1401            IAB & DISA Correspondence on DNS        January 1993   References   1. J.B. Postel and J.K. Reynolds, Domain Requirements,RFC 920,      October 1984.   2. P.V. Mockapetris, Domain Names - Concepts and Facilities,RFC 1034, November 1987.   3. P.V. Mockapetris, Domain Names - Implementation and Specification,RFC 1035, November 1987.   4. M.K. Stahl, Domain Administrators Guide,RFC 1032, November 1987.   5. M. Lottor, Domain Administrators Operations Guide,RFC 1033,      November 1987.   6. W.D. Lazear, MILNET Name Domain Transition,RFC 1031,      November 1987.IAB                                                             [Page 5]

RFC 1401            IAB & DISA Correspondence on DNS        January 19932.  Letter from DISA to the IAB                                                   16 APR 1992   Mr. Lyman Chapin   Chairman, Internet Activities Board   BBN Communications   Division of Bolt Beranek and Newman, Inc.   150 Cambridge Park Dr.   Chambridge, MA  02140   Dear Mr. Chapin:   We have received you letter concerning the adoption and use of the   Domain Name System (DNS) throughout the Internet.  Since the DoD   makes significant use of the Internet, we are very concerned with   issues such as the DNS that potentially affect both performance and   interoperability.  We have agreed to staff this issue to consider all   the technical and economical impacts on DoD systems.  We will inform   you of the decisions reached as the result of our reviews as son as   they are completed.                                   Sincerely,                                   Kenneth A. Thomas                                   Colonel, USA                                   Chairman, Protocol Standards                                     Steering Group (PSSG)   Copy to:   Mr. Pasquariello, Associate Director, Center for Standards   Mr. Schonborn, Deputy Director/DDN PMOIAB                                                             [Page 6]

RFC 1401            IAB & DISA Correspondence on DNS        January 19933.  Letter from the IAB to DISA   19 May, 1992   Colonel Kenneth Thomas   Chairman, Protocol Standards Steering Group   Defense Information Systems Agency   Fort Monmouth, NJ 07703-5613   Dear Colonel Thomas,   Thank you for your response to my letter concerning the adoption and   use of the Domain Name System throughout the Internet.  I appreciate   your willingness to devote resources to consider this issue, and look   forward to hearing the results of the study.   As LCDR David Chappell has suggested, it would be useful for us to   arrange a meeting to discuss issues of mutual concern to DISA and the   IAB.  I do not yet know if it will be feasible for me to arrange to   meet with you in Ft. Monmouth in the near future (my travel schedule   being somewhat oversubscribed), but will get in touch with you soon   to find a suitable date and location.   Regards,   A. Lyman Chapin   Chairman, Internet Activities Board   BBN Communications 20/5b   150 Cambridge Park Drive   Cambridge, MA 02140IAB                                                             [Page 7]

RFC 1401            IAB & DISA Correspondence on DNS        January 1993Security Considerations   Security issues are not discussed in this memo.Author's Address   A. Lyman Chapin   BBN Communications Corporation   150 Cambridge Park Drive   Cambridge, MA  02140   Phone: 617-873-3133   Fax:   617-873-4086   Email: Lyman@BBN.COMIAB                                                             [Page 8]