From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc921.txt | 741 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 741 insertions(+) create mode 100644 doc/rfc/rfc921.txt (limited to 'doc/rfc/rfc921.txt') diff --git a/doc/rfc/rfc921.txt b/doc/rfc/rfc921.txt new file mode 100644 index 0000000..e41cbb9 --- /dev/null +++ b/doc/rfc/rfc921.txt @@ -0,0 +1,741 @@ + + +Network Working Group Jon Postel +Request for Comments: 921 ISI + October 1984 +Updates: RFC 897, RFC 881 + + Domain Name System Implementation Schedule - Revised + + +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 an update of + RFC-881, and RFC-897. This is an official policy statement of the + IAB and the DARPA. Distribution of this memo is unlimited. + + 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 + + There are three aspects to the domain style naming system, (1) the + names themselves, (2) the method of translating names to addresses, + and (3) the relationship between the Internet and the rest of the + world. + + Names + + The names are being changed from simple names, or globally unique + strings, to structured names, where each component name is unique + only with respect to the superior component name. + + Simple Names + + Until recently, hosts in the DARPA research and DDN operational + communities were 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 + + Hierarchical Names + + Because of the growth of the Internet, structured names (or + domain style names) have been introduced. Each element of the + structured name will be a character string (with the same + constraints that previously applied to the simple names). The + + + + +Postel [Page 1] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + elements (or components) of the structured names are separated + with periods, and the elements are written from the most + specific on the left to the most general on the right. + + For example: USC-ISIF.ARPA + + The Initial and Temporary Domain + + The introduction of these hierarchical names has been very + limited. Every current name in this new system has the form + "old-simple-name.ARPA". That is, the all the hosts are in a + domain called "ARPA". This is a temporary situation. The + current intention is for the ARPA domain to cease to exist. + This means that all hosts will change their names as the domain + style names come into full use. + + Name to Address Lookup + + 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. This table is called + "HOSTS.TXT" [8] and is normally accessed via the Hostnames + Server [9]. + + 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. + + For example, + + OBERST%EDUCOM.MAILNET@MIT-MULTICS.ARPA + EDMISTON.CIC@CSNET-RELAY.ARPA + + + + + + + +Postel [Page 2] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + +The Future Situation + + Names + + Hierarchical Names + + The use of the hierarchical names will be greatly expanded + according to the rules established in the "Domain Requirements" + memo (RFC-920) [5]. + + For example: F.ISI.USC.EDU + + There are several levels of development for use of the domain + style names. + + First, there is the current simple substitution of the domain + style names for the old style host names. At this stage all + domain style names directly translate to host addresses (using the + NIC tables) and all domain style names have two components. The + mail system uses addresses of the form "local-part@host", where + host is a domain style host name. + + For example: USC-ISIF.ARPA and Postel@USC-ISIF.ARPA + + 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" in some old style file. + + Second, there is an extension to more name components and more top + level domains. The mail system still uses addresses of the form + "local-part@host", where host is a domain style host name. + + For example: F.ISI.USC.EDU and Postel@F.ISI.USC.EDU + + Here we expect that "F.ISI.USC.EDU" is the name of an Internet + host and that we can send mail for "Postel" to the SMTP port on + that host. It is likely that the NIC will enter these new + domain style names in the centrally maintained table (i.e., + HOSTS.TXT) during the transition period. 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 acts for such entities may require a level of + + + +Postel [Page 3] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + indirection in the search. The mail system may use + "local-part@domain-name", where the "domain-name" identifies a + host (as before) or an organization. + + For example: USC-ISI.EDU and Postel@USC-ISI.EDU + + Here we don't count on "USC-ISI. EDU" 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.EDU". + The server will tell us the name (and address) of a real + Internet host that handles mail on this organizations behalf, + for example, "F.ISI.USC.EDU = 10.2.0.52". We then send mail + for "Postel@USC-ISI.EDU" to the SMTP port on F.ISI.USC.EDU. + + Name to Address Lookup + + 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 lookup server. There will be a number of + servers that each hold a portion of the name to address + information. + + The maintenance of the translation data base will be subdivided + and distributed. + + The design and implementation details for this service are given + in RFC-882 [2] and RFC-883 [3]. + + 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 + + When we want to send mail to "Oberst" we ask the domain name + server about sending mail to "EDUCOM.MAILNET". The server will + tell us the name (and address) of a real Internet host that + handles mail on this organizations behalf, for example, + "MIT-MULTICS.ARPA = 10.0.0.6". We then send mail for + "Oberst@EDUCOM.MAILNET" to the SMTP port on MIT-MULTICS.ARPA. + + +Postel [Page 4] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + For example, + + Edmiston@CIC.CSNET + + When we want to send mail to "Edmiston" we ask the domain name + server about sending mail to "CIC.CSNET". The server will tell + us the name (and address) of a real Internet host that handles + mail on this organizations behalf, for example, + "CSNET-RELAY.ARPA = 10.4.0.5". We then send mail for + "Edmiston@CIC.CSNET" to the SMTP port on CSNET-RELAY.ARPA. + +The Transition Situation + + Actually, the situation is a bit more complicated, of course. 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 ensure that all + hosts do this, and then to eliminate the use 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 two steps to the transition plan. + + First, change from old names to domain style names. + + Second, change from using central tables to using name servers. + + There are two communities that are taking slightly different courses + in this transition. The DARPA 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 + + + +Postel [Page 5] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + 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. + + Interface to the World + + The interchange of mail with "other-systems" will have to continue + pretty much as it has (except that RELAY-HOST is 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 specify a mail-relay host. + +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? + + 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. + + Suppose one host changed its name from FOO to BAR. Mail that + was sent from FRED@FOO to JOE@ABC can not be answered unless + the change of name is known to the user or the mail program at + ABC and the host name BAR substituted for FOO. Mail that is + sent to JOE@ABC from SAM@DEF with a cc to FRED@FOO can not be + answered easily. + + Any mailing lists that have mailboxes with 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. + + + + +Postel [Page 6] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + 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. + + To 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 + + Currently, host have an official or primary names and may have + several nicknames. For example, + + Primary Name Nicknames + + USC-ISIF.ARPA USC-ISIF ISIF + + ADA-VAX.ARPA ADA-VAX ISI-VAXB AJPO VAXB + + The data base is 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 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 zones. + + + + + + + + + + + + + + + + + + + +Postel [Page 7] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + +The Revised Time Table + + There are three major phases to the implementation of the domain + names system: (1) putting the machinery in place (servers, + resolvers), (2) getting the data base installed, (3) changing the + user programs (mailers, etc.). + + The machinery is now (at last) well along, there is a server for + TOPS-20, and two different servers for Unix. The data base now + contains the ARPA domain and is initialized for the other top + level domains. Little has been done to change user programs to + use the new procedures. + + Done + + Service Design and Specification: The design and specification + for the protocol and data base were published (RFC-882, RFC-883). + + Domain Requirements Specification: The requirements for + establishing a new domain are published as an RFC (RFC-920). + + Domain Style Names in Table: Hosts are 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. + + Servers for ARPA Domain: Several domain name servers are in + operation to supply host name to internet address translations, + one of these servers is at the NIC. + + 15 Dec 84 Domain Table + + A master table of top level domain names and their associated + servers is established at the NIC. Probably this information will + be added to the HOSTS.TXT file as a new entry type. + + 15 Jan 85 Begin New Domain Registration + + New domains may register according to the procedures and + restrictions described in RFC-920 [5]. + + 15 Feb 85 Major Machinery Completed + + The principal servers are up and running, there are resolvers + programmed and tested for the most popular systems (Unix 4.2bsd, + TOPS-20). + + + +Postel [Page 8] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + 15 May 85 Significant Use of Resolvers and Servers + + Programs (e.g., Mailers, Telnet, FTP) begin regular use of the new + mechanisms (resolvers and servers). This may be done by changing + the programs to act as resolvers themselves and call on servers + directly, or to provide system calls that include the resolver + function to replace old system calls that accessed the host table. + + 15 Jul 85 Implementation of the Domain Naming System Completed + + The goal is to complete the switch over to the domain style names + and the use of the servers by this date. All programs that + translate host name to Internet addresses should now use + procedures based on the use of the domain style names system of + resolvers and servers and the distributed data base. + + 15 Sep 85 Decommission Host Table + + At this point the master host table maintained by the NIC need no + longer be complete for the DARPA research community. A full table + of the DDN operational hosts will be maintained by the NIC. + + 15 Oct 85 DDN Plan for Domains Name Service + + The DDN PMO may establish a plan for the future support of name to + address translations in the DDN community. + + + + + + + + + + + + + + + + + + + + + + + +Postel [Page 9] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + +Appendix : The Old Time Table + + Here we present the time table from the previous schedule (RFC-897) + with some comments on what was and was not accomplished. + + -- 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 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. + + + + + + +Postel [Page 10] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + 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. + + + + 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 DARPA research community. A full table + of the DDN operational hosts will be maintained by the NIC. + + + + + + +Postel [Page 11] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + + 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. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Postel [Page 12] + + + +RFC 921 October 1984 +Domain Implementation Schedule - Revised + + +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. + + [4] Postel, J., "Domain Name System Implementation Schedule", + RFC-897, USC Information Sciences Institute, February 1984. + + [5] Postel, J., and J. Reynolds, "Domain Requirements", RFC-920, USC + Information Sciences Institute, October 1984. + + [6] Mockapetris, P., "The Domain Name System", Proceedings of the + IFIP 6.5 Working Conference on Computer Message Services, + Nottingham, England, May 1984. Also as ISI/RS-84-133, + June 1984. + + [7] Mockapetris, P., J. Postel, and P. Kirton, "Name Server Design + for Distributed Systems", Proceedings of the Seventh + International Conference on Computer Communication, Sidney, + Australia, October 1984. Also as ISI/RS-84-132, June 1984. + + [8] Feinler, E., K. Harrenstien, Z. Su, and V. White, "DoD Internet + Host Table Specification", RFC-810, Network Information Center, + SRI International, March 1982. + + [9] Harrenstien, K., V. White, and E. Feinler, "Hostnames Server", + RFC-811, Network Information Center, SRI International, + March 1982. + + + + + + + + + + + + + + +Postel [Page 13] + -- cgit v1.2.3