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diff --git a/doc/rfc/rfc1706.txt b/doc/rfc/rfc1706.txt new file mode 100644 index 0000000..5b5d821 --- /dev/null +++ b/doc/rfc/rfc1706.txt @@ -0,0 +1,563 @@ + + + + + + +Network Working Group B. Manning +Request for Comments: 1706 ISI +Obsoletes: 1637, 1348 R. Colella +Category: Informational NIST + October 1994 + + + DNS NSAP Resource Records + + +Status of this Memo + + This memo provides information for the Internet community. This memo + does not specify an Internet standard of any kind. Distribution of + this memo is unlimited. + +Abstract + + OSI lower layer protocols, comprising the connectionless network + protocol (CLNP) and supporting routing protocols, are deployed in + some parts of the global Internet. Maintenance and debugging of CLNP + connectivity is greatly aided by support in the Domain Name System + (DNS) for mapping between names and NSAP addresses. + + This document defines the format of one new Resource Record (RR) for + the DNS for domain name-to-NSAP mapping. The RR may be used with any + NSAP address format. + + NSAP-to-name translation is accomplished through use of the PTR RR + (see STD 13, RFC 1035 for a description of the PTR RR). This paper + describes how PTR RRs are used to support this translation. + + This document obsoletes RFC 1348 and RFC 1637. + + + + + + + + + + + + + + + + + + +Manning & Colella [Page 1] + +RFC 1706 DNS NSAP RRs October 1994 + + +1. Introduction + + OSI lower layer protocols, comprising the connectionless network + protocol (CLNP) [5] and supporting routing protocols, are deployed in + some parts of the global Internet. Maintenance and debugging of CLNP + connectivity is greatly aided by support in the Domain Name System + (DNS) [7] [8] for mapping between names and NSAP (network service + access point) addresses [6] [Note: NSAP and NSAP address are used + interchangeably throughout this memo]. + + This document defines the format of one new Resource Record (RR) for + the DNS for domain name-to-NSAP mapping. The RR may be used with any + NSAP address format. + + NSAP-to-name translation is accomplished through use of the PTR RR + (see RFC 1035 for a description of the PTR RR). This paper describes + how PTR RRs are used to support this translation. + + This memo assumes that the reader is familiar with the DNS. Some + familiarity with NSAPs is useful; see [1] or Annex A of [6] for + additional information. + +2. Background + + The reason for defining DNS mappings for NSAPs is to support the + existing CLNP deployment in the Internet. Debugging with CLNP ping + and traceroute has become more difficult with only numeric NSAPs as + the scale of deployment has increased. Current debugging is supported + by maintaining and exchanging a configuration file with name/NSAP + mappings similar in function to hosts.txt. This suffers from the lack + of a central coordinator for this file and also from the perspective + of scaling. The former describes the most serious short-term + problem. Scaling of a hosts.txt-like solution has well-known long- + term scaling difficiencies. + +3. Scope + + The methods defined in this paper are applicable to all NSAP formats. + + As a point of reference, there is a distinction between registration + and publication of addresses. For IP addresses, the IANA is the root + registration authority and the DNS a publication method. For NSAPs, + Annex A of the network service definition, ISO8348 [6], describes the + root registration authority and this memo defines how the DNS is used + as a publication method. + + + + + + +Manning & Colella [Page 2] + +RFC 1706 DNS NSAP RRs October 1994 + + +4. Structure of NSAPs + + NSAPs are hierarchically structured to allow distributed + administration and efficient routing. Distributed administration + permits subdelegated addressing authorities to, as allowed by the + delegator, further structure the portion of the NSAP space under + their delegated control. Accomodating this distributed authority + requires that there be little or no a priori knowledge of the + structure of NSAPs built into DNS resolvers and servers. + + For the purposes of this memo, NSAPs can be thought of as a tree of + identifiers. The root of the tree is ISO8348 [6], and has as its + immediately registered subordinates the one-octet Authority and + Format Identifiers (AFIs) defined there. The size of subsequently- + defined fields depends on which branch of the tree is taken. The + depth of the tree varies according to the authority responsible for + defining subsequent fields. + + An example is the authority under which U.S. GOSIP defines NSAPs [2]. + Under the AFI of 47, NIST (National Institute of Standards and + Technology) obtained a value of 0005 (the AFI of 47 defines the next + field as being two octets consisting of four BCD digits from the + International Code Designator space [3]). NIST defined the subsequent + fields in [2], as shown in Figure 1. The field immediately following + 0005 is a format identifier for the rest of the U.S. GOSIP NSAP + structure, with a hex value of 80. Following this is the three-octet + field, values for which are allocated to network operators; the + registration authority for this field is delegated to GSA (General + Services Administration). + + The last octet of the NSAP is the NSelector (NSel). In practice, the + NSAP minus the NSel identifies the CLNP protocol machine on a given + system, and the NSel identifies the CLNP user. Since there can be + more than one CLNP user (meaning multiple NSel values for a given + "base" NSAP), the representation of the NSAP should be CLNP-user + independent. To achieve this, an NSel value of zero shall be used + with all NSAP values stored in the DNS. An NSAP with NSel=0 + identifies the network layer itself. It is left to the application + retrieving the NSAP to determine the appropriate value to use in that + instance of communication. + + When CLNP is used to support TCP and UDP services, the NSel value + used is the appropriate IP PROTO value as registered with the IANA. + For "standard" OSI, the selection of NSel values is left as a matter + of local administration. Administrators of systems that support the + OSI transport protocol [4] in addition to TCP/UDP must select NSels + for use by OSI Transport that do not conflict with the IP PROTO + values. + + + +Manning & Colella [Page 3] + +RFC 1706 DNS NSAP RRs October 1994 + + + |--------------| + | <-- IDP --> | + |--------------|-------------------------------------| + | AFI | IDI | <-- DSP --> | + |-----|--------|-------------------------------------| + | 47 | 0005 | DFI | AA |Rsvd | RD |Area | ID |Sel | + |-----|--------|-----|----|-----|----|-----|----|----| + octets | 1 | 2 | 1 | 3 | 2 | 2 | 2 | 6 | 1 | + |-----|--------|-----|----|-----|----|-----|----|----| + + IDP Initial Domain Part + AFI Authority and Format Identifier + IDI Initial Domain Identifier + DSP Domain Specific Part + DFI DSP Format Identifier + AA Administrative Authority + Rsvd Reserved + RD Routing Domain Identifier + Area Area Identifier + ID System Identifier + SEL NSAP Selector + + Figure 1: GOSIP Version 2 NSAP structure. + + + In the NSAP RRs in Master Files and in the printed text in this memo, + NSAPs are often represented as a string of "."-separated hex values. + The values correspond to convenient divisions of the NSAP to make it + more readable. For example, the "."-separated fields might correspond + to the NSAP fields as defined by the appropriate authority (RARE, + U.S. GOSIP, ANSI, etc.). The use of this notation is strictly for + readability. The "."s do not appear in DNS packets and DNS servers + can ignore them when reading Master Files. For example, a printable + representation of the first four fields of a U.S. GOSIP NSAP might + look like + + 47.0005.80.005a00 + + and a full U.S. GOSIP NSAP might appear as + + 47.0005.80.005a00.0000.1000.0020.00800a123456.00. + + Other NSAP formats have different lengths and different + administratively defined field widths to accomodate different + requirements. For more information on NSAP formats in use see RFC + 1629 [1]. + + + + + +Manning & Colella [Page 4] + +RFC 1706 DNS NSAP RRs October 1994 + + +5. The NSAP RR + + The NSAP RR is defined with mnemonic "NSAP" and TYPE code 22 + (decimal) and is used to map from domain names to NSAPs. Name-to-NSAP + mapping in the DNS using the NSAP RR operates analogously to IP + address lookup. A query is generated by the resolver requesting an + NSAP RR for a provided domain name. + + NSAP RRs conform to the top level RR format and semantics as defined + in Section 3.2.1 of RFC 1035. + + 1 1 1 1 1 1 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | | + / / + / NAME / + | | + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | TYPE = NSAP | + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | CLASS = IN | + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | TTL | + | | + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | RDLENGTH | + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + / RDATA / + / / + +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + + where: + + * NAME: an owner name, i.e., the name of the node to which this + resource record pertains. + + * TYPE: two octets containing the NSAP RR TYPE code of 22 (decimal). + + * CLASS: two octets containing the RR IN CLASS code of 1. + + * TTL: a 32 bit signed integer that specifies the time interval in + seconds that the resource record may be cached before the source + of the information should again be consulted. Zero values are + interpreted to mean that the RR can only be used for the + transaction in progress, and should not be cached. For example, + SOA records are always distributed with a zero TTL to prohibit + caching. Zero values can also be used for extremely volatile data. + + + +Manning & Colella [Page 5] + +RFC 1706 DNS NSAP RRs October 1994 + + + * RDLENGTH: an unsigned 16 bit integer that specifies the length in + octets of the RDATA field. + + * RDATA: a variable length string of octets containing the NSAP. + The value is the binary encoding of the NSAP as it would appear in + the CLNP source or destination address field. A typical example of + such an NSAP (in hex) is shown below. For this NSAP, RDLENGTH is + 20 (decimal); "."s have been omitted to emphasize that they don't + appear in the DNS packets. + + 39840f80005a0000000001e13708002010726e00 + + NSAP RRs cause no additional section processing. + +6. NSAP-to-name Mapping Using the PTR RR + + The PTR RR is defined in RFC 1035. This RR is typically used under + the "IN-ADDR.ARPA" domain to map from IPv4 addresses to domain names. + + Similarly, the PTR RR is used to map from NSAPs to domain names under + the "NSAP.INT" domain. A domain name is generated from the NSAP + according to the rules described below. A query is sent by the + resolver requesting a PTR RR for the provided domain name. + + A domain name is generated from an NSAP by reversing the hex nibbles + of the NSAP, treating each nibble as a separate subdomain, and + appending the top-level subdomain name "NSAP.INT" to it. For example, + the domain name used in the reverse lookup for the NSAP + + 47.0005.80.005a00.0000.0001.e133.ffffff000162.00 + + would appear as + + 0.0.2.6.1.0.0.0.f.f.f.f.f.f.3.3.1.e.1.0.0.0.0.0.0.0.0.0.a.5.0.0. \ + 0.8.5.0.0.0.7.4.NSAP.INT. + + [Implementation note: For sanity's sake user interfaces should be + designed to allow users to enter NSAPs using their natural order, + i.e., as they are typically written on paper. Also, arbitrary "."s + should be allowed (and ignored) on input.] + +7. Master File Format + + The format of NSAP RRs (and NSAP-related PTR RRs) in Master Files + conforms to Section 5, "Master Files," of RFC 1035. Below are + examples of the use of these RRs in Master Files to support name-to- + NSAP and NSAP-to-name mapping. + + + + +Manning & Colella [Page 6] + +RFC 1706 DNS NSAP RRs October 1994 + + + The NSAP RR introduces a new hex string format for the RDATA field. + The format is "0x" (i.e., a zero followed by an 'x' character) + followed by a variable length string of hex characters (0 to 9, a to + f). The hex string is case-insensitive. "."s (i.e., periods) may be + inserted in the hex string anywhere after the "0x" for readability. + The "."s have no significance other than for readability and are not + propagated in the protocol (e.g., queries or zone transfers). + + + ;;;;;; + ;;;;;; Master File for domain nsap.nist.gov. + ;;;;;; + + + @ IN SOA emu.ncsl.nist.gov. root.emu.ncsl.nist.gov. ( + 1994041800 ; Serial - date + 1800 ; Refresh - 30 minutes + 300 ; Retry - 5 minutes + 604800 ; Expire - 7 days + 3600 ) ; Minimum - 1 hour + IN NS emu.ncsl.nist.gov. + IN NS tuba.nsap.lanl.gov. + ; + ; + $ORIGIN nsap.nist.gov. + ; + ; hosts + ; + bsdi1 IN NSAP 0x47.0005.80.005a00.0000.0001.e133.ffffff000161.00 + IN A 129.6.224.161 + IN HINFO PC_486 BSDi1.1 + ; + bsdi2 IN NSAP 0x47.0005.80.005a00.0000.0001.e133.ffffff000162.00 + IN A 129.6.224.162 + IN HINFO PC_486 BSDi1.1 + ; + cursive IN NSAP 0x47.0005.80.005a00.0000.0001.e133.ffffff000171.00 + IN A 129.6.224.171 + IN HINFO PC_386 DOS_5.0/NCSA_Telnet(TUBA) + ; + infidel IN NSAP 0x47.0005.80.005a00.0000.0001.e133.ffffff000164.00 + IN A 129.6.55.164 + IN HINFO PC/486 BSDi1.0(TUBA) + ; + ; routers + ; + cisco1 IN NSAP 0x47.0005.80.005a00.0000.0001.e133.aaaaaa000151.00 + IN A 129.6.224.151 + + + +Manning & Colella [Page 7] + +RFC 1706 DNS NSAP RRs October 1994 + + + IN A 129.6.225.151 + IN A 129.6.229.151 + ; + 3com1 IN NSAP 0x47.0005.80.005a00.0000.0001.e133.aaaaaa000111.00 + IN A 129.6.224.111 + IN A 129.6.225.111 + IN A 129.6.228.111 + + + + + ;;;;;; + ;;;;;; Master File for reverse mapping of NSAPs under the + ;;;;;; NSAP prefix: + ;;;;;; + ;;;;;; 47.0005.80.005a00.0000.0001.e133 + ;;;;;; + + + @ IN SOA emu.ncsl.nist.gov. root.emu.ncsl.nist.gov. ( + 1994041800 ; Serial - date + 1800 ; Refresh - 30 minutes + 300 ; Retry - 5 minutes + 604800 ; Expire - 7 days + 3600 ) ; Minimum - 1 hour + IN NS emu.ncsl.nist.gov. + IN NS tuba.nsap.lanl.gov. + ; + ; + $ORIGIN 3.3.1.e.1.0.0.0.0.0.0.0.0.0.a.5.0.0.0.8.5.0.0.0.7.4.NSAP.INT. + ; + 0.0.1.6.1.0.0.0.f.f.f.f.f.f IN PTR bsdi1.nsap.nist.gov. + ; + 0.0.2.6.1.0.0.0.f.f.f.f.f.f IN PTR bsdi2.nsap.nist.gov. + ; + 0.0.1.7.1.0.0.0.f.f.f.f.f.f IN PTR cursive.nsap.nist.gov. + ; + 0.0.4.6.1.0.0.0.f.f.f.f.f.f IN PTR infidel.nsap.nist.gov. + ; + 0.0.1.5.1.0.0.0.a.a.a.a.a.a IN PTR cisco1.nsap.nist.gov. + ; + 0.0.1.1.1.0.0.0.a.a.a.a.a.a IN PTR 3com1.nsap.nist.gov. + +8. Security Considerations + + Security issues are not discussed in this memo. + + + + + +Manning & Colella [Page 8] + +RFC 1706 DNS NSAP RRs October 1994 + + +9. Authors' Addresses + + Bill Manning + USC/Information Sciences Institute + 4676 Admiralty Way + Marina del Rey, CA. 90292 + USA + + Phone: +1.310.822.1511 + EMail: bmanning@isi.edu + + + Richard Colella + National Institute of Standards and Technology + Technology/B217 + Gaithersburg, MD 20899 + USA + + Phone: +1 301-975-3627 + Fax: +1 301 590-0932 + EMail: colella@nist.gov + +10. References + + [1] Colella, R., Gardner, E., Callon, R., and Y. Rekhter, "Guidelines + for OSI NSAP Allocation inh the Internet", RFC 1629, NIST, + Wellfleet, Mitre, T.J. Watson Research Center, IBM Corp., May + 1994. + + [2] GOSIP Advanced Requirements Group. Government Open Systems + Interconnection Profile (GOSIP) Version 2. Federal Information + Processing Standard 146-1, U.S. Department of Commerce, National + Institute of Standards and Technology, Gaithersburg, MD, April + 1991. + + [3] ISO/IEC. Data interchange - structures for the identification of + organization. International Standard 6523, ISO/IEC JTC 1, + Switzerland, 1984. + + [4] ISO/IEC. Connection oriented transport protocol specification. + International Standard 8073, ISO/IEC JTC 1, Switzerland, 1986. + + [5] ISO/IEC. Protocol for Providing the Connectionless-mode Network + Service. International Standard 8473, ISO/IEC JTC 1, + Switzerland, 1986. + + + + + + +Manning & Colella [Page 9] + +RFC 1706 DNS NSAP RRs October 1994 + + + [6] ISO/IEC. Information Processing Systems -- Data Communications -- + Network Service Definition. International Standard 8348, ISO/IEC + JTC 1, Switzerland, 1993. + + [7] Mockapetris, P., "Domain Names -- Concepts and Facilities", STD + 13, RFC 1034, USC/Information Sciences Institute, November 1987. + + [8] Mockapetris, P., "Domain Names -- Implementation and + Specification", STD 13, RFC 1035, USC/Information Sciences + Institute, November 1987. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Manning & Colella [Page 10] + |