📄 rfc1034.4up.ps
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S%%Page: (9-12) 3%%BeginPageSetup_S24 818 translate%Page: (9) 9%BeginPageSetup_S% N-up sub-page 1/40 -392 translate0.490859 dup scale/pagenum 9 def/fname (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/rfc1034.txt) def/fdir (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/) def/ftail (rfc1034.txt) def% User defined strings:/fmodstr (Tue Nov 24 00:00:00 1987) def/pagenumstr (9) def/user_header_p true def/user_header_left_str (RFC1034) def/user_header_center_str (RFC.net) def/user_header_right_str (Page 9 of 56) def%%EndPageSetupdo_header5 751 M(RFC 1034 Domain Concepts and Facilities November 1987) s5 712 M(hand, and that different parts of the tree can have different implied) s5 699 M(semantics. For example, the IN-ADDR.ARPA domain is organized and) s5 686 M(distributed by network and host address because its role is to translate) s5 673 M(from network or host numbers to names; NetBIOS domains [RFC-1001, RFC-) s5 660 M(1002] are flat because that is appropriate for that application.) s5 634 M(However, there are some guidelines that apply to the "normal" parts of) s5 621 M(the name space used for hosts, mailboxes, etc., that will make the name) s5 608 M(space more uniform, provide for growth, and minimize problems as) s5 595 M(software is converted from the older host table. The political) s5 582 M(decisions about the top levels of the tree originated in RFC-920.) s5 569 M(Current policy for the top levels is discussed in [RFC-1032]. MILNET) s5 556 M(conversion issues are covered in [RFC-1031].) s5 530 M(Lower domains which will eventually be broken into multiple zones should) s5 517 M(provide branching at the top of the domain so that the eventual) s5 504 M(decomposition can be done without renaming. Node labels which use) s5 491 M(special characters, leading digits, etc., are likely to break older) s5 478 M(software which depends on more restrictive choices.) s5 452 M(3.3. Technical guidelines on use) s5 426 M(Before the DNS can be used to hold naming information for some kind of) s5 413 M(object, two needs must be met:) s5 387 M( - A convention for mapping between object names and domain) s5 374 M( names. This describes how information about an object is) s5 361 M( accessed.) s5 335 M( - RR types and data formats for describing the object.) s5 309 M(These rules can be quite simple or fairly complex. Very often, the) s5 296 M(designer must take into account existing formats and plan for upward) s5 283 M(compatibility for existing usage. Multiple mappings or levels of) s5 270 M(mapping may be required.) s5 244 M(For hosts, the mapping depends on the existing syntax for host names) s5 231 M(which is a subset of the usual text representation for domain names,) s5 218 M(together with RR formats for describing host addresses, etc. Because we) s5 205 M(need a reliable inverse mapping from address to host name, a special) s5 192 M(mapping for addresses into the IN-ADDR.ARPA domain is also defined.) s5 166 M(For mailboxes, the mapping is slightly more complex. The usual mail) s5 153 M(address <local-part>@<mail-domain> is mapped into a domain name by) s5 140 M(converting <local-part> into a single label \(regardles of dots it) s5 127 M(contains\), converting <mail-domain> into a domain name using the usual) s5 114 M(text format for domain names \(dots denote label breaks\), and) s5 101 M(concatenating the two to form a single domain name. Thus the mailbox) s5 49 M(Mockapetris [Page 9]) s_R%Page: (10) 10%BeginPageSetup_S% N-up sub-page 2/4278 -392 translate0.490859 dup scale/pagenum 10 def/fname (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/rfc1034.txt) def/fdir (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/) def/ftail (rfc1034.txt) def% User defined strings:/fmodstr (Tue Nov 24 00:00:00 1987) def/pagenumstr (10) def/user_header_p true def/user_header_left_str (RFC1034) def/user_header_center_str (RFC.net) def/user_header_right_str (Page 10 of 56) def%%EndPageSetupdo_header5 751 M(RFC 1034 Domain Concepts and Facilities November 1987) s5 712 M(HOSTMASTER@SRI-NIC.ARPA is represented as a domain name by) s5 699 M(HOSTMASTER.SRI-NIC.ARPA. An appreciation for the reasons behind this) s5 686 M(design also must take into account the scheme for mail exchanges [RFC-) s5 673 M(974].) s5 647 M(The typical user is not concerned with defining these rules, but should) s5 634 M(understand that they usually are the result of numerous compromises) s5 621 M(between desires for upward compatibility with old usage, interactions) s5 608 M(between different object definitions, and the inevitable urge to add new) s5 595 M(features when defining the rules. The way the DNS is used to support) s5 582 M(some object is often more crucial than the restrictions inherent in the) s5 569 M(DNS.) s5 543 M(3.4. Example name space) s5 517 M(The following figure shows a part of the current domain name space, and) s5 504 M(is used in many examples in this RFC. Note that the tree is a very) s5 491 M(small subset of the actual name space.) s5 465 M( |) s5 452 M( |) s5 439 M( +---------------------+------------------+) s5 426 M( | | |) s5 413 M( MIL EDU ARPA) s5 400 M( | | |) s5 387 M( | | |) s5 374 M( +-----+-----+ | +------+-----+-----+) s5 361 M( | | | | | | |) s5 348 M( BRL NOSC DARPA | IN-ADDR SRI-NIC ACC) s5 335 M( |) s5 322 M( +--------+------------------+---------------+--------+) s5 309 M( | | | | |) s5 296 M( UCI MIT | UDEL YALE) s5 283 M( | ISI) s5 270 M( | |) s5 257 M( +---+---+ |) s5 244 M( | | |) s5 231 M( LCS ACHILLES +--+-----+-----+--------+) s5 218 M( | | | | | |) s5 205 M( XX A C VAXA VENERA Mockapetris) s5 179 M(In this example, the root domain has three immediate subdomains: MIL,) s5 166 M(EDU, and ARPA. The LCS.MIT.EDU domain has one immediate subdomain named) s5 153 M(XX.LCS.MIT.EDU. All of the leaves are also domains.) s5 127 M(3.5. Preferred name syntax) s5 101 M(The DNS specifications attempt to be as general as possible in the rules) s5 49 M(Mockapetris [Page 10]) s_R%Page: (11) 11%BeginPageSetup_S% N-up sub-page 3/40 -794 translate0.490859 dup scale/pagenum 11 def/fname (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/rfc1034.txt) def/fdir (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/) def/ftail (rfc1034.txt) def% User defined strings:/fmodstr (Tue Nov 24 00:00:00 1987) def/pagenumstr (11) def/user_header_p true def/user_header_left_str (RFC1034) def/user_header_center_str (RFC.net) def/user_header_right_str (Page 11 of 56) def%%EndPageSetupdo_header5 751 M(RFC 1034 Domain Concepts and Facilities November 1987) s5 712 M(for constructing domain names. The idea is that the name of any) s5 699 M(existing object can be expressed as a domain name with minimal changes.) s5 686 M(However, when assigning a domain name for an object, the prudent user) s5 673 M(will select a name which satisfies both the rules of the domain system) s5 660 M(and any existing rules for the object, whether these rules are published) s5 647 M(or implied by existing programs.) s5 621 M(For example, when naming a mail domain, the user should satisfy both the) s5 608 M(rules of this memo and those in RFC-822. When creating a new host name,) s5 595 M(the old rules for HOSTS.TXT should be followed. This avoids problems) s5 582 M(when old software is converted to use domain names.) s5 556 M(The following syntax will result in fewer problems with many) s5 543 M(applications that use domain names \(e.g., mail, TELNET\).) s5 517 M(<domain> ::= <subdomain> | " ") s5 491 M(<subdomain> ::= <label> | <subdomain> "." <label>) s5 465 M(<label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]) s5 439 M(<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>) s5 413 M(<let-dig-hyp> ::= <let-dig> | "-") s5 387 M(<let-dig> ::= <letter> | <digit>) s5 361 M(<letter> ::= any one of the 52 alphabetic characters A through Z in) s5 348 M(upper case and a through z in lower case) s5 322 M(<digit> ::= any one of the ten digits 0 through 9) s5 296 M(Note that while upper and lower case letters are allowed in domain) s5 283 M(names, no significance is attached to the case. That is, two names with) s5 270 M(the same spelling but different case are to be treated as if identical.) s5 244 M(The labels must follow the rules for ARPANET host names. They must) s5 231 M(start with a letter, end with a letter or digit, and have as interior) s5 218 M(characters only letters, digits, and hyphen. There are also some) s5 205 M(restrictions on the length. Labels must be 63 characters or less.) s5 179 M(For example, the following strings identify hosts in the Internet:) s5 153 M(A.ISI.EDU XX.LCS.MIT.EDU SRI-NIC.ARPA) s5 127 M(3.6. Resource Records) s5 101 M(A domain name identifies a node. Each node has a set of resource) s5 49 M(Mockapetris [Page 11]) s_R%Page: (12) 12%BeginPageSetup_S% N-up sub-page 4/4278 -794 translate0.490859 dup scale/pagenum 12 def/fname (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/rfc1034.txt) def/fdir (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/) def/ftail (rfc1034.txt) def% User defined strings:/fmodstr (Tue Nov 24 00:00:00 1987) def/pagenumstr (12) def/user_header_p true def/user_header_left_str (RFC1034) def/user_header_center_str (RFC.net) def/user_header_right_str (Page 12 of 56) def%%EndPageSetupdo_header5 751 M(RFC 1034 Domain Concepts and Facilities November 1987) s5 712 M(information, which may be empty. The set of resource information) s5 699 M(associated with a particular name is composed of separate resource) s5 686 M(records \(RRs\). The order of RRs in a set is not significant, and need) s5 673 M(not be preserved by name servers, resolvers, or other parts of the DNS.) s5 647 M(When we talk about a specific RR, we assume it has the following:) s5 621 M(owner which is the domain name where the RR is found.) s5 595 M(type which is an encoded 16 bit value that specifies the type) s5 582 M( of the resource in this resource record. Types refer to) s5 569 M( abstract resources.) s5 543 M( This memo uses the following types:) s5 517 M( A a host address) s5 491 M( CNAME identifies the canonical name of an) s5 478 M( alias) s5 452 M( HINFO identifies the CPU and OS used by a host) s5 426 M( MX identifies a mail exchange for the) s5 413 M( domain. See [RFC-974 for details.) s5 387 M( NS) s5 374 M( the authoritative name server for the domain) s5 348 M( PTR) s5 335 M( a pointer to another part of the domain name space) s5 309 M( SOA) s5 296 M( identifies the start of a zone of authority]) s5 270 M(class which is an encoded 16 bit value which identifies a) s5 257 M( protocol family or instance of a protocol.) s5 231 M( This memo uses the following classes:) s5 205 M( IN the Internet system) s5 179 M( CH the Chaos system) s5 153 M(TTL which is the time to live of the RR. This field is a 32) s5 140 M( bit integer in units of seconds, an is primarily used by) s5 127 M( resolvers when they cache RRs. The TTL describes how) s5 114 M( long a RR can be cached before it should be discarded.) s5 49 M(Mockapetris [Page 12]) s_R_RS%%Page: (13-16) 4%%BeginPageSetup_S24 818 translate%Page: (13) 13%BeginPageSetup_S% N-up sub-page 1/40 -392 translate0.490859 dup scale/pagenum 13 def/fname (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/rfc1034.txt) def/fdir (/usr/local/share/doc/rfc/Mirrors/ftp.isi.edu/in-notes/) def/ftail (rfc1034.txt) def% User defined strings:/fmodstr (Tue Nov 24 00:00:00 1987) def⌨️ 快捷键说明
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