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diff --git a/doc/rfc/rfc897.txt b/doc/rfc/rfc897.txt new file mode 100644 index 0000000..9e0ffd2 --- /dev/null +++ b/doc/rfc/rfc897.txt @@ -0,0 +1,456 @@ + + +Network Working Group Jon Postel +Request for Comments: 897 ISI + February 1984 +Updates: RFC 881 + + Domain Name System Implementation Schedule + + +Status of this Memo + + This memo is a policy statement on the implementation of the Domain + Style Naming System in the Internet. This memo is a partial update + of RFC 881. This is an official policy statement of the ICCB and the + DARPA. + + The intent of this memo is to detail the schedule for the + implementation for the Domain Style Naming System. The explanation + of how this system works is to be found in the references. + +The Current Situation + + Simple Names + + Hosts in the ARPA research and DDN operational communities are + currently assigned names in a flat or global name space of + character strings. There are some limits on these names. They + must start with a letter, end with a letter or digit and have only + letters or digits or hyphen as interior characters. Case is not + significant. + + For example: USC-ISIF + + Tables + + Every host in the Internet is expected to have a way of + translating the name of any other host into its Internet address. + + By and large, the name to address translation is done by looking + up the information in a table of all hosts. + + The maintenance of this table is centralized at the Network + Information Center (NIC). Each host is expected to obtain a + current copy of the table on a timely basis. + + Interface to the World + + A great deal of mail moves between the Internet and other + "systems" that somehow transport mail among computers. This is + currently done by hiding some sort of "other-system" addressing + information in the local-part of the mail address and using a + mail-relay host in the host-part of the mailbox. + + +Postel [Page 1] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + For example, + + OBERST%EDUCOM.MAILNET@MIT-MULTICS + EDMISTON.CIC@CSNET-RELAY + +The Future Situation + + Hierarchical Names + + Because of the growth of the Internet, structured names (or domain + style names) will be used. Each element of the structured name + will be a character string (with the same constraints that + previously applied to the simple names). + + For example: F.ISI.USC.ARPA + + Servers + + Every host in the Internet will be expected to have a way of + translating the name of any other host into its Internet address. + + By and large, the name to address translation will be done by + interacting with a service. There will be a number of servers + that each hold a portion of the name to address information. + + The maintenance of the translation data will be subdivided and + distributed. + + There are several stages of implementation for the servers and + several levels of development for use of the domain style names. + + First, there is the simple substitution of the domain style names + for the current host names, and the subdivision of these into + several domains. At this stage all domain style names directly + translate to host addresses and all domain style names have two + components. + + For example: USC-ISIF.ARPA or USC-ISIA.DDN + + and: Postel@USC-ISIF.ARPA or Kahn@USC-ISIA.DDN + + Here we expect that "USC-ISIF.ARPA" is the name of an Internet + host and that we can send mail for "Postel" to the SMTP port on + that host. It may be that some backward host can still fake it + by ignoring the ".ARPA" and looking up an address for + "USC-ISIF". + + + +Postel [Page 2] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + Using the domain name servers (but not the tables) mail + forwarding may be supported. A domain name server query can + say "I want to send mail to ABCDEF.ARPA". The response might + be "to send mail to ABCDEF.ARPA send it to the mail relay + GHIJKL.ARPA at address 123.123.123.123". + + Second, there is an extension to more name components. + + For example: F.ISI.USC.ARPA or A.USC-ISI.DDN + + and: Postel@F.ISI.USC.ARPA or Kahn@A.USC-ISI.DDN + + Here we expect that "F.ISI.USC.ARPA" is the name of an Internet + host and that we can send mail for "Postel" to the SMTP port on + that host. It is unlikely that a backward host can hack this + at all. + + Third, there is an extension to domain style names that may + represent only organizations or administrative entities. Finding + a host that represents such entities may require a level of + indirection in the search. + + For example: USC-ISI.ARPA or ARPA.DDN + + and: Postel@USC-ISI.ARPA or Kahn@ARPA.DDN + + Here we don't count on "USC-ISI.ARPA" being the name of an + Internet host. When we want to send mail to "Postel" we ask + the domain name server about sending mail to "USC-ISI.ARPA". + The server will tell us the name (and address) of a real + Internet host that handles mail on this organizations behalf, + for example, "F.USC-ISI.ARPA = 10.2.0.52". We then send mail + for "Postel" to the SMTP port on F.USC-ISI.ARPA. + + Interface to the World + + Mail will continue to move between the Internet and other + "systems". This may be done by designating some sort of + "other-system" representative organization in the domain server + data bases that can indirect mail to a mail-relay host. + + For example, + + OBERST@EDUCOM.MAILNET + EDMISTON@CIC.CSNET + + + + +Postel [Page 3] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + +The Transition Situation + + Actually, the situation is a bit more complicated, of course. A + number of hosts are already using domain style names under the + constraint that their domain style name is exactly their old style + name with the string ".ARPA" appended. The first transition step is + to have all hosts do this, and then to eliminate the user of old + style names altogether. + + Please note carefully that two types of changes are being made: + + One is a change in the support mechanism for translating a host + name to an internet address, + + that is from using local copies of a full centrally maintained + table to dynamically accessing a distributed set of servers + each posesing a portion of a data base maintained in a + distributed fashion. + + The other is a change in the host names themselves, + + from a flat global space of unstructured strings to a + hierarchical structure of names. + + There are four steps to the transition plan. + + First, change from old names to domain style names. + + host-name --> host-name.ARPA + + Second, one domain to a few domains. + + host-name.ARPA --> host-name.ARPA and host-name.DDN + + Third, change from using central tables to using name servers. + + Fourth, allow many domains. + + There are two communities that are taking slightly different courses + in this transition. The ARPA research community is making the full + transition. The DDN operational community is making the change in + naming on the same schedule, but is not requiring hosts in the DDN + operational community make the change to using servers at the same + time (they can if they want to). The DDN PMO will establish a + schedule for that change at a later time. The NIC will maintain a + central table of all DDN operational hosts. + + + +Postel [Page 4] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + Interface to the World + + The interchange of mail with "other-systems" will have to continue + pretty much as it does now (except that RELAY-HOST will become + RELAY-HOST.ARPA) until organization names can be used. Then + representative organizations can be designated for each + "other-system" in the domain server data bases that will then + indirectly specify a mail-relay host. + +Policy Statement + + The names of hosts will be changed to domain style names. Hosts will + begin to use domain style names on 14-Mar-84 and the use of old style + names will be completely phased out before 2-May-84. + + This applies to both the ARPA research hosts and the DDN operational + hosts. + +Implication + + All Hosts Change Names + + The impact of introducing the domain style names is that all hosts + change their names at least once. Hosts that move to new domains + or subdomains may change their names several times. + + Hosts have an official (or primary) name and possibly several + nicknames. When mail is sent from a host, the official name is + used in the mail header address fields. + + Suppose, that in the old days before domains were thought of, a + host changed its name. What is the impact on users of changing + the name of a host? Suppose one host changed its name from FOO to + BAR. + + Mail + + Mail that was sent before the name was changed can not be + answered using mail program commands that automatically fill + in the return address. While it may be possible to use + special tricks to fix up the "From" or the "To" users + addresses, the "Cc" addresses are very difficult to correct. + + Mail that was sent to JOE@ABC from FRED@FOO can not be + answered unless the change of name is known to the user or + the mail program an ABC and the host name BAR substituted + for FOO. + + +Postel [Page 5] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + Mail that is sent to JOE@ABC from SAM@DEF with a cc to + FRED@FOO can not be answered easily. + + Mailing Lists + + Any mailing lists that have mailboxes on the host that + changed names will now have incorrect entries. + + The point is that while the host that changed names may be able to + use special tricks for a while to fix things up for the users, it + is difficult for other hosts to do this. + + A general trick is to make the old name a nickname for the host + for some period of time. + + The introduction of domain style names means that all hosts change + their names essentially at the same time. + + For example, USC-ISIF changes to USC-ISIF.ARPA + + To lessen the resulting havoc, the initial set of new names has a + fixed relationship to the old names. The first set of domain + style names is exactly the old names with the domain name "ARPA" + appended. That is, if a hosts old name was "HOST-NAME", then its + new name is "HOST-NAME.ARPA". + + To further lessen the havoc, there will be a period of time when + both the old and the new names are allowed. That is, the old + names will be nicknames for a while. + + Primary Names + + In to old style names, host have an official or primary names and + may have several nicknames. For example, + + Primary Name Nicknames + + USC-ISIF ISIF + + ADA-VAX ISI-VAXB AJPO VAXB + + In any case, the data base in such than given any of the names for + a host one can find the address, and given the address one can + find the primary name. + + In the new domain style name system this property must be + maintained. That is, given the Internet address of a host one + + +Postel [Page 6] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + must be able to find the primary name of that host. This calls + for careful management of the distributed database by those in + charge of the domains and subdomains. + +The Time Table + + -- Nov 83 Plan and Schedule + + At this point the overall plan for the implementation of domain + style names and name servers, and a schedule of events was + published (RFC-881). Also the draft design and specification for + the protocol and data base were published (RFC-882, RFC-883). + + -- Nov 83 Initial Domain Style Host Name Table + + At this point a version of the host table which includes the + domain style names is made available (DHOSTS.TXT). + + -- Feb 84 Domain Requirements Specification + + At this point the requirements for establishing a new domain are + published as an RFC. + + 14 Mar 84 Begin using Domain Style Names + + At this point all hosts should start using their domain style + names as their official and primary names. The standard table of + host names contains domain style names as the official and primary + name (DHOSTS.TXT becomes HOSTS.TXT). + + 04 Apr 84 Server for ARPA Domain + + At this point several domain name servers are in operation to + supply host name to internet address translations, one of these + servers is at the NIC. + + 04 Apr 84 Domain Table + + At this point a master table of top level domain names and their + associated servers is established at the NIC. + + 02 May 84 Stop using old style Names + + At this point the use of old style names must be completely phased + out. + + + + +Postel [Page 7] + + + +RFC 897 February 1984 +Domain Implementation Schedule + + + 02 May 84 Certain New Domains + + At this point a few new domains may be established, in particular + the DDN domain. + + 06 Jun 84 General & Multilevel Domains + + At this point additional new domains may be established, if they + meet the requirements. Domain style names may have more than two + segments. + + 18 Jul 84 Organizational Domains + + Domain style names may identify organizations. Finding an address + for a host may involve a level of indirection. + + 05 Sep 84 Decommission Host Table + + At this point the master host table maintained by the NIC need no + longer be complete for the ARPA research community. A full table + of the DDN operational hosts will be maintained by the NIC. + + 03 Oct 84 DDN Plan for Domains Name Service + + At this point the DDN PMO will establish a plan for the future + support of name to address translations in the DDN community. + +References + + [1] Postel, J., "The Domain Names Plan and Schedule", RFC-881, USC + Information Sciences Institute, November 1983. + + [2] Mockapetris, P., "Domain Names - Concepts and Facilities", + RFC-882, USC Information Sciences Institute, November 1983. + + [3] Mockapetris, P., "Domain Names - Implementation and + Specification", RFC-883, USC Information Sciences Institute, + November 1983. + + + + + + + + + + + +Postel [Page 8] + |