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rfc:rfc2167

Network Working Group S. Williamson Request for Comments: 2167 M. Kosters Obsoletes: RFC 1714 D. Blacka Category: Informational J. Singh

                                                           K. Zeilstra
                                               Network Solutions, Inc.
                                                             June 1997
               Referral Whois (RWhois) Protocol V1.5

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

 This memo describes Version 1.5 of the client/server interaction of
 RWhois.  RWhois provides a distributed system for the discovery,
 retrieval, and maintenance of directory information. This system is
 primarily hierarchical by design. It allows for the deterministic
 routing of a query based on hierarchical tags, referring the user
 closer to the maintainer of the information. While RWhois can be
 considered a generic directory services protocol, it distinguishes
 itself from other protocols by providing an integrated, hierarchical
 architecture and query routing mechanism.

1. Introduction

 Early in the development of the ARPANET, the SRI-NIC established a
 centralized Whois database that provided host and network information
 about the systems connected to the network and the electronic mail
 (email) addresses of the users on those systems [RFC 954]. The
 ARPANET experiment evolved into a global network, the Internet, with
 countless people and hundreds of thousands of end systems. The sheer
 size and effort needed to maintain a centralized database
 necessitates an alternate, decentralized approach to storing and
 retrieving this information.

Williamson, et. al. Informational [Page 1] RFC 2167 RWhois Protocol June 1997

 The original Whois function was to be a central directory of
 resources and people on ARPANET. However, it could not adequately
 meet the needs of the expanded Internet. RWhois extends and enhances
 the Whois concept in a hierarchical and scaleable fashion. In
 accordance with this, RWhois focuses primarily on the distribution of
 "network objects", or the data representing Internet resources or
 people, and uses the inherently hierarchical nature of these network
 objects (domain names, Internet Protocol (IP) networks, email
 addresses) to more accurately discover the requested information.
 RWhois synthesizes concepts from other, established Internet
 protocols. The RWhois protocol and architecture derive a great deal
 of structure from the Domain Name System (DNS) [RFC 1034] and borrow
 directory service concepts from other directory service efforts,
 primarily [X.500]. The protocol is also influenced by earlier
 established Internet protocols, such as the Simple Mail Transport
 Protocol (SMTP) [RFC 821].
 This RWhois specification defines both a directory access protocol
 and a directory architecture. The directory access protocol
 specifically describes the syntax of the client/server interaction.
 It describes how an RWhois client can search for data on an RWhois
 server, or how the client can modify data on the server. It also
 describes how the server is to interpret input from the client, and
 how the client should interpret the results returned by the server.
 The architecture portion of this document describes the conceptual
 framework behind the RWhois protocol. It details the concepts upon
 which the protocol is based and describes its structural elements.
 The protocol implements the architecture.
 This document uses language like SHOULD and SHALL that have special
 meaning as specified in "Key words for use in RFCs to Indicate
 Requirement Levels". [RFC2119]

Williamson, et. al. Informational [Page 2] RFC 2167 RWhois Protocol June 1997

2. Architecture

2.1 Overview

 As a directory service, RWhois is a distributed database, where data
 is split across multiple servers to keep database sizes manageable.
 The architecture portion of this document details the concepts upon
 which the protocol is based and describes its structural elements.
 Specifically, the architecture is concerned with how the data is
 split across the different servers. The basis of this splitting is
 the lexically hierarchical label (or tag), which is a text string
 whose position in a hierarchy can be determined from the structure of
 the string itself.
 All data can follow some sort of hierarchy, even if the hierarchy
 seems somewhat arbitrary. For example, person names can be arranged
 into hierarchical groups via geography. If all the people in
 particular towns are grouped into town groups, then all of the town
 groups can be grouped into state (or province) groups, and then all
 of the state groups can be grouped into a country group. Then, a
 particular name would belong in a town group, a state group, and a
 country group. However, just given a name, it would be impossible to
 determine where in the hierarchy it belongs.  Therefore, a person
 name is not lexically hierarchical.
 However, there are certain types of data whose position in the
 hierarchy can be determined by deciphering the data itself, for
 example, phone numbers. A phone number is grouped according to
 country code, area code, local exchange, and local extension. By
 looking at a phone number, it is possible to determine to which of
 all these groups the number belongs:  1-303-555-2367 is in country
 code 1, area code 303, local exchange 555, and has a local extension
 of 2367. Therefore, a phone number is lexically hierarchical.
 On the Internet, two such types of data are widely used: domain names
 and IP networks. Domain names are organized via a label-dot system,
 reading from a more specific label to a more general label left to
 right; for example, war.west.netsol.com is a part of west.netsol.com,
 which is a part of netsol.com, which is a part of com. IP networks
 are also lexically hierarchical labels using the Classless Inter-
 Domain Routing (CIDR) notation, but their hierarchy is not easily
 determined with simple text manipulation; for example, 198.41.0.0/22
 is a part of 198.41.0.0/16, which is a part of 198.40.0.0/15.
 Instead, an IP network's hierarchy is determined by converting the
 network to binary notation and applying successively shorter bit
 masks.

Williamson, et. al. Informational [Page 3] RFC 2167 RWhois Protocol June 1997

 It is important to note that, while very little real data is
 lexically hierarchical in nature, people often create label systems
 (or namespaces) to help manage the data and provide an element of
 uniqueness, for example, Social Security Numbers, ISBNs, or the Dewey
 Decimal System. RWhois leverages lexically hierarchical labels,
 domain names and IP networks, for its data splitting using the
 concepts of authority areas and referrals. An authority area is
 associated with an RWhois server and a lexically hierarchical label,
 which is considered to be its name. An authority area is a piece of
 the distributed database that speaks with authority about its
 assigned part of the hierarchy. All data associated with a particular
 lexically hierarchical tag should be located within that authority
 area's database. Authority areas are further explained in Section
 2.4.
 RWhois directs clients toward the appropriate authority area by
 generating referrals. Referrals are pointers to other servers that
 are presumed to be closer to the desired data. The client uses this
 referral to contact the next server and ask the same question. The
 next server may respond with data, an error, or another referral (or
 referrals). By following this chain of referrals, the client will
 eventually reach the server with the appropriate authority area. In
 the RWhois architecture, referrals are generated by identifying a
 lexically hierarchical label and deciphering the label to determine
 the next server. Referrals are further explained in Section 2.5.
 When a number of RWhois servers containing authority areas are
 brought on line and informed about each other, they form an RWhois
 tree. The tree has a root authority area, which is the group that
 contains all other groups.  The root authority area must keep
 pointers to the servers and authority areas that form the first level
 of the hierarchy. The authority areas in the first level of the
 hierarchy are then responsible for keeping pointers to the authority
 areas below them and for keeping a pointer to the root.

2.2 Design Philosophy

 The design goals for the RWhois protocol are as follows.
  • It should be a directory access protocol. The server should be

able to access and update the data residing on it.

  • It should facilitate query routing. An unresolved query should

be redirected to a server that is presumed to be closer to the

      desired data.
    * It should enable data replication. The server should be able to
      duplicate its data on another server.
    * The server should be lightweight and delegate more functions to
      the client.

Williamson, et. al. Informational [Page 4] RFC 2167 RWhois Protocol June 1997

 The concepts used to achieve these design goals are explained in the
 remaining document.

2.3 Schema Model

 As a directory service, RWhois uses various database schema to store
 and represent data. Schema, in this document, has two definitions.
 First, it refers to the entire structure of a database, all the
 tables and fields forming a complete database. When schema is used in
 this context, it is called the "database schema". Database schema
 consists of attributes, classes, and objects. Schema may also refer
 to a single piece of the database, a single table with fields. When
 schema is used in this context, it is just called "schema" or it is
 preceded by the name of the particular piece: contact schema or
 domain schema, for example. In this usage, schema is equivalent to
 "class", defined below.
 There is no standard database schema in the RWhois architecture. Each
 authority area is presumed to be able to define its own local schema.
 However, an authority area that is part of a larger RWhois tree is
 expected to have some part of its schema pertain to the lexically
 hierarchical label upon which the RWhois tree is based. An authority
 area schema may not change throughout much of an RWhois tree.

2.3.1 Attributes

 An attribute is a named field and is the smallest typed unit in the
 database schema. It is equivalent to a relational database's field.
 An attribute is not considered to be data by itself; it is simply
 used to give data a type. When a piece of data has been typed by an
 attribute, it is typically referred to as a value and is represented
 as an attribute-value pair. The RWhois syntax for the attribute-value
 pair is to separate them with a colon, for example:
 First-Name:Bill
 Attributes have a number of properties, some mandated by the RWhois
 protocol and some that are implementation dependent. These properties
 are usually a reflection of the database system used by the server.
 The following is a list of the protocol-mandated properties and their
 descriptions.
  Attribute    This is the name of the attribute.
  Description  This is a natural language description of the
               attribute.

Williamson, et. al. Informational [Page 5] RFC 2167 RWhois Protocol June 1997

  Type         This is a parameter that broadly indicates the use
               of the attribute to the protocol. There are three
               standard types:  TEXT, ID, and SEE-ALSO. The default is
               TEXT, which indicates that the value is a text string.
               ID indicates that the attribute contains the ID of
               another RWhois object. This type of attribute is used
               for database normalization.  SEE-ALSO indicates that
               the attribute contains a pointer (a Uniform Resource
               Identifier (URI)) to some other kind of external data;
               for example, a World Wide Web page or FTP site.
  Format       This is an interpretable string that describes the
               acceptance format of the value. The server (and
               optionally the client) should match the value to the
               format string to determine if the value is acceptable.
               The format of this property is a keyword indicating the
               syntax of the format string, followed by a colon,
               followed by the format string itself. Currently, the
               only keyword recognized is "re" for POSIX.2 extended
               regular expressions.
  Indexed      This is a true or false flag indicating that this
               attribute should be indexed (and therefore able to be
               searched).
  Required     This is a true or false flag indicating that this
               attribute must have a value in an instance of the
               class.
  Multi-Line   This is a true or false flag indicating that this
               attribute may have multiple instances in a class, but
               all of the instances are to be considered as multiple
               lines of the same attribute instance. This allows
               normal line terminators to terminate values.
  Repeatable   This is a true or false flag indicating that there may
               be multiple instances of this attribute in a class and
               each instance is to be interpreted as a separate
               instance (in contrast to Multi-Line). This flag is
               mutually exclusive with Multi-Line: if Multi-Line is
               true, then Repeatable must be false and vice versa.

Williamson, et. al. Informational [Page 6] RFC 2167 RWhois Protocol June 1997

  Primary      This is a true or false flag that indicates that this
               attribute is a primary key. If more than one attribute
               in a class is marked as primary, then these attributes
               together form a single primary key. The primary key is
               intended to be used to force uniqueness among class
               instances. Therefore, there can be only one instance of
               a primary key in a database. The Primary flag implies
               that the attribute is also required.
  Hierarchical This is a true or false flag that indicates that this
               attribute is lexically hierarchical.
  Private      This is a true or false flag that indicates whether or
               not this attribute is private (that is, publicly not
               viewable).  It defaults to false. If it is true, then
               only the clients that satisfy the
               authentication/encryption requirements of a guardian
               (described below) are able to view the attribute-value
               pair.

2.3.2 Class

 A class is a collection of attributes; it is a structure, not data.
 The concept is equivalent to that of a relational database table. It
 is also equivalent to the second definition of schema, above.
 A class also has some properties that are sometimes referred to as
 its "meta" information. These properties are listed below.
  Version     This is a time/date stamp that is used to quickly detect
              when a class definition has been changed.
  Description This is a natural language description of the class.

2.3.3 Object

 An object is an instance of a class. It is data with a type of
 <class>.

2.3.4 Base Class

 While RWhois does not have or advocate using a specific, standardized
 schema, it does impose a few requirements. It requires that all
 defined classes inherit attributes from a particular base class (or
 base schema).  The RWhois specification does not require the actual
 implementation of inheritance. Instead, all classes must include the
 attributes defined in the base class.

Williamson, et. al. Informational [Page 7] RFC 2167 RWhois Protocol June 1997

 The base class has the following attributes.
  Class-Name    This attribute contains the name of the class to which
                the object belongs. It is the type of the object
                itself. It is of type TEXT and is required.
  Auth-Area     This attribute contains the name of the authority area
                to which the object belongs. It, along with Class-
                Name, definitively defines the type of the object. It
                is of type TEXT and is required.
  ID            This attribute is a universal identifier for the
                object. It is formed by choosing a string that is
                unique within an authority area and appending the
                authority area to it, separating the local string from
                the authority area name with a period. The only
                restrictions on the local string are that it must be
                unique within the authority area and not contain the
                period character. This attribute is hierarchical in
                nature. It is always generated by the server (for
                example, during a register operation). It is of type
                TEXT and is required.
  Updated       This attribute is a time/date stamp that indicates the
                time of last modification of the object. It is both
                informational and a form of record locking. It
                prevents two clients from modifying the same object at
                the same time. It is of type TEXT and is required.
  Guardian      This attribute is a link to a guardian object
                (described below). Its value is the ID of a guardian
                object. It is of type ID and is optional. It is
                repeatable, since an object may have multiple
                guardians.
  Private      This attribute is a true or false flag that indicates
                whether or not an object is private (that is, publicly
                not viewable). It defaults to false. If it is true,
                then only the clients that satisfy the
                authentication/encryption requirements of one of the
                object's guardians are able to view the object. If the
                object is publicly viewable, then the Private
                attribute property of each of its attributes still
                applies.

Williamson, et. al. Informational [Page 8] RFC 2167 RWhois Protocol June 1997

  TTL           This attribute is the "time-to-live" of a given
                object. It is included only if an object has a
                different time-to-live than the default given in the
                Start of Authority information. Its value is specified
                in seconds. It is of type TEXT and is optional.
 The RWhois specification defines two standard classes that should be
 included in all implementations: the referral and guardian classes.

2.3.5 Referral Class

 The referral class is defined to hold referral information (typically
 for link referrals). It consists of attributes defined as part of the
 base class, the protocol-specific attributes described below, and any
 installation-specific attributes.
  Referred-Auth-Area This attribute contains the name of the authority
                     area to which the referral points. It is used as
                     a search key during the query routing. It is of
                     type TEXT and is required. It is repeatable,
                     since referrals can point to servers hosting more
                     than one authority area.
  Referral           This attribute contains the referral itself. It
                     is an RWhois URL. It is of type TEXT and is
                     required. It is repeatable, since more than one
                     server can host a Referred-Auth-Area.

2.3.6 Guardian Class

 The guardian class is defined to hold security information. The
 fundamental concept behind the guardian class is that an object (or
 another structure) is "guarded" by containing a pointer to a guardian
 object [Guardian]. To modify, delete, or possibly view the guarded
 object, the authentication (or encryption, or both) scheme must be
 satisfied. Guardians are intended to not have rank: if an object is
 guarded by more than one guardian object, satisfying any one of those
 guardians is sufficient. A guardian object that does not have any
 Guardian attribute linking it to other guardians guards itself. That
 is, the authentication scheme in the guardian object itself must be
 satisfied to modify, delete, or possibly view it.
 Guardian objects are typically linked to actual database objects with
 the Guardian attribute found in the base class. However, a guardian
 may also be linked to an entire authority area, in which case the
 guardian becomes implicitly linked to all of the objects contained
 within the authority area.

Williamson, et. al. Informational [Page 9] RFC 2167 RWhois Protocol June 1997

 The guardian class consists of the base class, the protocol-specific
 attributes described below, and any installation-specific attributes.
  Guard-Scheme This attribute contains a keyword indicating the
               authentication methodology. Its value must be
               understood by both the client and server, and its value
               dictates the contents of the Guard-Info attribute. It
               is of type TEXT and is required.
  Guard-Info   This attribute contains that data that is used by the
               Guard-Scheme to verify the authentication. Its actual
               format is dictated by the Guard-Scheme, for example, it
               could contain a password or Pretty Good Privacy (PGP)
               public key id [RFC 1991]. For security reasons, it
               should not be displayed, and its Private attribute
               property should be set to true. It is of type TEXT and
               is required.

2.4 Authority Areas

 The concept of authority areas is pivotal to the RWhois architecture.
 When an RWhois tree is created for a particular lexically
 hierarchical namespace, the different pieces of the hierarchy are
 mapped to authority areas. The most important concept behind an
 authority area is the ability for a portion of the RWhois tree to
 definitively control that portion of the hierarchy. This means that
 an authority area is able to state whether or not a hierarchical tag
 is in the whole RWhois tree. It does this either by returning the
 object containing this tag, returning a referral to a sub-authority
 area, or returning a response indicating that no objects were found.
 This structure enables efficient routing of queries based on the
 hierarchical label to the piece of the hierarchy responsible for it.
 For example, in the domain name namespace as served by RWhois, the
 root of the tree would be an authority area named ".", which would
 delegate a "us" sub-authority area, which would delegate "va", "co",
 "md", and "ca" authority areas, and so forth. When the server with
 the "va.us" authority area is asked about "loudoun.va.us", it will be
 able to authoritatively state that either no "loudoun.va.us" exists
 or it will provide an object for or a referral to "loudoun.va.us".
 Further, if the server is asked about "howard.md.us", it cannot
 answer authoritatively, so it must provide a referral to its
 hierarchical parent ("us" or the root).
 This use of authority area strongly indicates where data should be
 stored within an RWhois tree. Because RWhois uses a specific query
 routing model, data needs to be placed under the proper authority
 area. It is certainly possible to place a piece of data under the

Williamson, et. al. Informational [Page 10] RFC 2167 RWhois Protocol June 1997

 wrong authority area, for example, putting an object for
 "howard.md.us" under the "va.us" authority area. In such cases, the
 data is considered to be misplaced and unable to be found within the
 RWhois tree. However, while data should be placed under the lowest
 (most specific) authority area, it is also possible that it could be
 placed in a higher (least specific) authority area, for example,
 putting an object for "loudoun.va.us" under the "us" authority. This
 may be acceptable since, in most cases, the data would be able to be
 found.
 In addition to controlling a part of an RWhois hierarchy, an
 authority area is considered to be autonomous. Each authority area is
 treated as a separate database by the protocol. However, it is
 recommended that an authority area share some core schema with the
 rest of the RWhois tree for interoperability reasons. Each authority
 area, however, is not bound by the database schema of its
 hierarchical parent or by any of its sub-authority areas.

2.5 Query Routing

 RWhois is not only a directory access protocol but it can also route
 queries. Routing a query involves redirecting the query to another
 server that is presumed to be closer to the desired data. To route a
 query, the server first determines the location of the next server.
 It then either forwards the query to that server and returns the
 result to the client or returns the location of that server to the
 client. The location of the server must contain its host name (or IP
 address), port number, and authority area.
 The location of the server to which a query is routed is called a
 referral.  There are two types of referrals: punt and link referrals.
 A punt referral is a pointer to a server that is further up an RWhois
 tree, and a link referral is a pointer to a server that is further
 down the tree. For example, in Figure 1, when the server for the
 "va.us" authority area routes a query up to the server for the "us"
 authority area, it generates a punt referral. Alternatively, when it
 routes a query down to the server for the "loudon.va.us" authority
 area, it generates a link referral.
 Query routing depends on whether or not the search value in a query
 is lexically hierarchical. If the search value is hierarchical, the
 server can generate punt or link referrals using the association of
 authority areas with lexically hierarchical labels. Otherwise, the
 server may send the query to a special index server that gathers the
 indexing information for both hierarchical and non-hierarchical data
 from the directory servers and returns referrals to these servers
 [CIP]. If the server receives one or more referrals from the index
 server, it should return them to the client.

Williamson, et. al. Informational [Page 11] RFC 2167 RWhois Protocol June 1997

 It is important to note that the server may route a query whether it
 could resolve the query or not. Even if a query has been resolved
 locally, the server may also return referrals to the client by
 sending the query to the index server. For example, if the server for
 the "com" authority area receives the "domain Org-Name=IBM" query, it
 may return all the domain objects for IBM within the "com" authority
 area. In addition, it may also return referrals to the server for the
 "nl" authority area if that server contains domain objects for IBM in
 the Netherlands and has fed the corresponding indexing information to
 the index server. This way the client can get back information for
 both "ibm.com" and "ibm.nl" domains.

2.5.1 Query Routing Rules

 An RWhois server routes a query based on certain rules. The objective
 is to determine the location of a server to which to route the query.
 A query may contain one or more query terms. The query routing rules
 are applied on each query term until a referral is found. The rules
 are listed below.
  • Is the search value in the query term hierarchical? If not, go

to the next query term.

  • Parse the hierarchical portion of the search value. Is it is

within one of the authority areas? If not, go to the next query

      term.
    * Does the found authority area have any referral objects
      (instances of the referral class)? If not, return the "230 No
      objects found" error to the client.
    * Is the hierarchical portion of the search value within the
      Referred-Auth-Area attribute of one of the referral objects? If
      it is, return the value of the Referral attribute of the found
      referral object as a link referral to the client.
    * Are the search values of some of the query terms hierarchical
      but not within any of the authority areas? If they are, return a
      punt referral to the client.
    * Are the search values of all the query terms non-hierarchical?
      If they are, send the query to a special index server that
      gathers the indexing information for both hierarchical and non-
      hierarchical data from the directory servers and returns
      referrals to these servers. If the server receives one or more
      referrals from the index server, return them to the client.
 Note that there can be more than one referral returned to the client.
 These referrals may point to servers serving different authority
 areas. The client may follow them in any order.

Williamson, et. al. Informational [Page 12] RFC 2167 RWhois Protocol June 1997

 The pseudo code for the above rules is:
 for each query term in the query
  if the search value in the query term is hierarchical
   if the search value is within one of the authority areas
     if the search value is within one of the referred authority areas
      the server sends link referral(s)
     else
      the server sends a "230 No objects found" error
     endif
   endif
  endif
 endfor
 if the search values of some of the query terms are hierarchical but
   not within any of the authority areas
  the server sends Punt referral(s)
 endif
 if the search values of all the query terms are non-hierarchical
  the server sends Referral(s) from an index server
 endif

2.6 Data Replication

 An RWhois server can replicate (duplicate) data from another RWhois
 server on a per-authority area basis. Data replication makes the
 RWhois service more reliable. Further, it increases throughput by
 distributing queries to more than one server.
 There can be two types of servers serving an authority area: a master
 server and a slave server. A master server is where data is
 registered for an authority area. It answers authoritatively to
 queries in that authority area. There must be one and only one master
 server for an authority area. A master server is also called a
 primary server.
 A slave server is where data is replicated from the master server for
 an authority area. It also answers authoritatively to queries in that
 authority area. There may be one or more slave servers for an
 authority area. A slave server is also called a secondary server.
 Note that a slave server must not register data for an authority
 area.
 It is recommended that the master and slave servers for an authority
 area be geographically separate. Therefore, network unreachability at
 one site will not completely shut down the RWhois service for that
 authority area.

Williamson, et. al. Informational [Page 13] RFC 2167 RWhois Protocol June 1997

2.6.1 Data to Replicate

 In RWhois, data is replicated on a per-authority area basis. The
 smallest type of data a slave server can replicate is an attribute of
 a class.  Therefore, a slave server can replicate data for all the
 classes, some classes, or some attributes of some classes.
 The amount of data a slave server can replicate each time is either
 all of the data or the data that has changed since the last
 replication. The process of replicating all of the data is called
 complete replication. The process of replicating the data that has
 changed since the last replication is called incremental replication.

2.6.2 Start Of Authority Variables

 Each authority area has some administrative variables, defined at the
 master server, to control data replication. These variables are
 called the Start Of Authority (SOA) variables. They are listed below.
  Serial-Number     This is the serial number of the data in an
                    authority area. The master server should update
                    this variable whenever the data in the authority
                    area is changed. Its value is a time/date stamp.
  Refresh-Interval  This is the time interval before a slave server
                    checks for complete replication. Its value is
                    specified in seconds.
  Increment-IntervalThis is the time interval before a slave server
                    checks for incremental replication. Its value is
                    specified in seconds.
  Retry-Interval    This is the time interval before a slave server
                    tries again to connect to a master server that
                    appears to be out-of-service. Its value is
                    specified in seconds.
  Time-To-Live      This is the default time to live for the data in
                    an authority area at a slave server. The slave
                    server should not answer authoritatively to
                    queries for such stale data. Its value is
                    specified in seconds.
  Admin-Contact     This is the email address of an individual or a
                    role account responsible for the data integrity in
                    an authority area at the master server.

Williamson, et. al. Informational [Page 14] RFC 2167 RWhois Protocol June 1997

  Tech-Contact      This is the email address of an individual or a
                    role account responsible for the operation of the
                    master server for an authority area.
  Hostmaster        This is the email address of an individual or a
                    role account to whom email messages to update the
                    data in an authority area at the master server are
                    sent.
  Primary-Server    This is the location of the master server for an
                    authority area. Its value must contain both the
                    host name (or IP address) and port number of the
                    master server.

3. Protocol

3.1 Overview

 The above sections describe the directory service architecture based
 on the RWhois protocol. The remaining sections describe the syntax of
 the protocol; the sequence and syntax of the information exchanged
 between a server and a client. There are five types of information
 that may be exchanged during a client/server session: directive,
 response, query, result, and info.

3.1.1 Directive

 A directive is a command that a client sends to a server to set a
 control parameter for the session, get the meta-information (class
 definitions and SOA information) about an authority area, or get the
 data in an authority area. The first character of a directive must be
 a "-". The server must support the "-rwhois" directive; all other
 directives are optional. The server must indicate in the banner which
 directives are implemented (see Section 3.1.9).

3.1.2 Response

 A response is the information that a server returns to a client for a
 directive. It is comprised of one or more lines, and the last line
 always indicates the success or failure of the directive. The first
 character of each response line must be a "%". If a server runs a
 directive successfully, the last response line must be "%ok".
 Otherwise, it must be "%error <error-code> <error-text>". A line with
 the string "%ok" or "%error" in the first position must occur only
 once in a server response and must always be the last line. The
 server may send the "%info" response for special messages.

Williamson, et. al. Informational [Page 15] RFC 2167 RWhois Protocol June 1997

 A client must understand the "%ok", "%error", and "%info" responses.
 The client must also understand directive specific responses, if it
 uses the related directives to communicate with the server. For
 example, if the client sends the "-schema" directive to the server,
 the client must understand the "%schema" response.

3.1.3 Query

 A query is a command that a client sends to a server to access the
 data in an authority area. The first character of a query must not be
 a "-", since the server checks the first character of each command
 from a client to determine whether it is a directive or a query.

3.1.4 Result

 A result is the information that a server returns to a client for a
 query.  It can be either the accessed data or referrals to other
 servers. It is comprised of one or more lines, and the last line
 always indicates the success or failure of the query. If a server
 returns either data or referrals for a query, the last result line
 must be "%ok". Otherwise, it must be "%error <error-code> <error-
 text>".

3.1.5 Info

 An info message contains miscellaneous information that a server
 sends to a client. The server may use it to send special messages,
 for example a "message of the day" (MOTD), to the client. The first
 info line must be "%info on", and the last info line must be "%info
 off".

3.1.6 Client/Server Session

 A typical RWhois client/server session has the following sequence of
 messages.
  • The client connects to the server.
  • The server returns a banner identifying its protocol versions

and capabilities.

  • The client sends one or more directives to the server.
  • The server returns the response to each directive.
  • The client finally sends a query to the server.
  • The server returns the query results.
  • The server closes the connection, unless the client has directed

it not to close the connection.

Williamson, et. al. Informational [Page 16] RFC 2167 RWhois Protocol June 1997

3.1.7 Examples

 This section gives some common examples of the client/server
 interaction.  The notation in the examples uses a prefix to indicate
 from where the information comes. A "C" indicates that the client
 sends the data to the server. An "S" indicates that the server sends
 the data to the client. The line is a comment when "#" is used. The
 space after the prefix is not part of the data.
 The following example illustrates a successful query.
 # The client connects to the server.
 # The server returns a banner identifying its protocol versions and
 # capabilities.
 S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)
 # The client sends a directive to limit the number of search hits
 # to 20.
 C -limit 20
 # The server returns a successful response.
 S %ok
 # The client sends a query to search for rwhois.net domain.
 C domain rwhois.net
 # The server returns the data for rwhois.net domain.
 S domain:ID:dom-1.rwhois.net
 S domain:Auth-Area:rwhois.net
 S domain:Class-Name:domain
 S domain:Updated:19970107201111000
 S domain:Domain:rwhois.net
 S domain:Server;I:hst-1.rwhois.net
 S domain:Server;I:hst-2.rwhois.net
 S
 S %ok
 # The server closes the connection.
 The following example illustrates the link and punt referrals.
 # The client connects to the server.
 # The server returns a banner identifying its protocol versions and
 # capabilities.
 S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)
 # The client sends a directive to hold the connection until it sends
 # a directive to close the connection.
 C -holdconnect on
 # The server returns a successful response.
 S %ok
 # The client sends a query to search for a.b.rwhois.net domain.
 C domain a.b.rwhois.net
 # The server returns a link referral to a server serving the

Williamson, et. al. Informational [Page 17] RFC 2167 RWhois Protocol June 1997

 # b.rwhois.net authority area.
 S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net
 S %ok
 # The client sends a query to search for internic.net domain.
 C domain internic.net
 # The server returns a punt referral to a server serving the root
 # authority area.
 S %referral rwhois://rs.internic.net:4321/auth-area=.
 S %ok
 # The client sends a directive to close the connection.
 C -quit
 S %ok
 # The server closes the connection.
 The following example illustrates a query error.
 # The client connects to the server.
 # The server returns a banner identifying its protocol versions and
 # capabilities.
 S %rwhois V-1.5:00ffff:00 master.rwhois.net (Network Solutions V-1.5)
 # The client sends a query to search for c.rwhois.net domain.
 C domain c.rwhois.net
 # The server returns an error, since neither data nor referrals for
 # c.rwhois.net domain are found within the rwhois.net authority area.
 S %error 230 No objects found
 # The server closes the connection.

3.1.8 Notation

 The following sections use the Augmented Backus-Naur Form (ABNF)
 notation to describe the syntax of the protocol. For further
 information, see Section 2 of [RFC822]. The notation in the examples
 uses a prefix to indicate from where the information comes. A "C"
 indicates that the client sends the data to the server. An "S"
 indicates that the server sends the data to the client. The line is a
 comment when "#" is used. The space after the prefix is not part of
 the data.

3.1.9 General ABNF definitions

 Lexical Tokens
 alpha = "a".."z" / "A".."Z"
 digit = "0".."9"
 hex-digit = digit / "a".."f" / "A".. "F"
 id-char = alpha / digit / "_" / "-"
 any-char = <ASCII 1..255,
            except LF (linefeed) and CR (carriage return)>

Williamson, et. al. Informational [Page 18] RFC 2167 RWhois Protocol June 1997

 dns-char = alpha / digit / "-"
 email-char = <see [RFC 822]>
 space = " "
 tab = <ASCII TAB (tab)>
 lf = <ASCII LF (linefeed)>
 cr = <ASCII CR (carriage return)>
 crlf = cr lf
 Grammar
 year = 4digit
 month = 2digit
 day = 2digit
 hour = 2digit
 minute = 2digit
 second = 2digit
 milli-second = 3digit
 host-name = dns-char *(dns-char / ".")
 ip-address = 1*3digit "." 1*3digit "." 1*3digit "." 1*3digit
 email = 1*email-char "@" host-name
 authority-area = (dns-char / ".") *(dns-char / "." / "/")
 object-id = 1*id-char "." authority-area
 host-port = (host-name / ip-address) ":" 1*5digit
 class-name = 1*id-char
 attribute-name = 1*id-char
 attribute-value = 1*any-char
 time-stamp = year month day hour minute second milli-second
 on-off = "on" / "off"
 Note that the time-stamp must be in the Greenwich Mean Time (GMT)
 time zone.  Also note that since in the above any-char is 1..255
 ASCII that the RWhois protocol is an 8 bit protocol.
 Response
 The general response for every directive and query is either "%ok" or
 "%error". In addition, a "%info" response may be sent.
 response = ok-response crlf / error-response crlf / info-response
 ok-response = "%ok"
 error-response = "%error" space error-code space error-text
 error-code = 3digit
 error-text = 1*any-char
 info-response = "%info" space "on" crlf *(*any-char crlf) "%info"
         space "off" crlf

Williamson, et. al. Informational [Page 19] RFC 2167 RWhois Protocol June 1997

 Banner
 The server must send a banner to the client when the connection is
 opened.  The banner contains the version(s) of the protocol the
 server supports and a capability ID of encoded bit flags that
 indicates which directives are implemented. If the server supports
 more than one version of the protocol, the lowest-numbered version
 must be specified first. The bits in extra-id are reserved for future
 use. The end of the banner should contain a free-form string
 indicating the name of the server implementation. A server must
 support at least one version of the protocol, and may accept more
 versions for compatibility reasons.
 rwhois-banner = "%rwhois" space version-list space host-name
       [space implementation] crlf
 version-list = version *("," version)
 version = version-number [":" capability-id]
         / "V-1.5" ":" capability-id
 version-number = "V-" 1*digit "." 1*digit
 capability-id = response-id ":" extra-id
 response-id = 6hex-digit
 extra-id = 2hex-digit
 implementation = 1*any-char
 Protocol
 The entire RWhois protocol can be defined as a series of directives,
 responses, queries, and results.
 rwhois-protocol = client-sends / server-returns
 client-sends = *(directives / rwhois-query)
 server-returns = *(responses / rwhois-query-result)

3.2 Required Directives

 The server must implement the following directives.

Williamson, et. al. Informational [Page 20] RFC 2167 RWhois Protocol June 1997

3.2.1 rwhois

 Description
 The "-rwhois" directive may be issued by the client at the start of
 every session . It tells the server which version of the protocol the
 client can handle. The server must respond with a banner containing
 the protocol version and directives it implements. This banner is the
 same banner that is sent by the server when the connection is opened,
 except that the server must indicate only one version number. The
 banner issued when opening a connection may contain more than one
 version number. The directive flags are encoded into three octets,
 which are described in Appendix D.
 ABNF
 rwhois-dir = "-rwhois" space version-number [space implementation]
              crlf
 rwhois-response = "%rwhois" space version space host-name
         [space implementation] crlf
 Errors
 300 Not compatible with version
 338 Invalid directive syntax
 Examples
 # When a connection is opened, the server issues the banner.
 S %rwhois V-1.0,V-1.5:00ffff:00 rs.internic.net (NSI Server 1.5.4)
 # The client sends the rwhois directive.
 C -rwhois V-1.5 NSI Client 1.2.3
 S %rwhois V-1.5:00ffff:00 rs.internic.net (NSI Server 1.5.4)
 S %ok

3.3 Optional Directives

 The server should implement the following directives.

Williamson, et. al. Informational [Page 21] RFC 2167 RWhois Protocol June 1997

3.3.1 class

 Description
 The "-class" directive can be used by the client to get the meta-
 information for one or more classes in an authority area. The
 response must contain the description and version number of each
 specified class and may be expanded in the future with additional
 attributes. When no class name is given, the server must return the
 meta-information for all the classes in the authority area. Every
 class record must end with an empty "%class" line.
 ABNF
 class-dir = "-class" space authority-area *(space class-name) crlf
 class-response = *class-record response
 class-record = *class-line "%class" crlf
 class-line = "%class" space class-name ":" "description" ":"
              1*any-char crlf
    / "%class" space class-name ":" "version" ":" time-stamp crlf
    / "%class" space class-name ":" meta-field ":" meta-value crlf
 meta-field = 1*id-char
 meta-value = 1*any-char
 The following fields are required.
  meta-field   meta-value  Description
  description  1*any-char  Class description.
                         Time/date stamp indicating version of class,
  version      time-stamp  must be updated after class definition is
                           changed.
 Errors
 338 Invalid directive syntax
 340 Invalid authority area
 341 Invalid class
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -class rwhois.net domain host
 S %class domain:description:Domain information
 S %class domain:version:19970103101232000
 S %class

Williamson, et. al. Informational [Page 22] RFC 2167 RWhois Protocol June 1997

 S %class host:description:Host information
 S %class host:version:19970214213241000
 S %class
 S %ok

3.3.2 directive

 Description
 The "-directive" directive can be used by the client to get
 information about the directives that the server supports. The
 response must contain the name and description of each specified
 directive and may be expanded in the future with additional
 attributes. When no directive name is given, the server must return
 information about all the directives. Every directive record must end
 with an empty "%directive" line.
 ABNF
 directive-dir = "-directive" *(space directive-name) crlf
 directive-name = 1*id-char
 directive-response = *directive-record response
 directive-record = "%directive" space "directive" ":" directive-name
                    crlf *directive-line "%directive" crlf
 directive-line = "%directive" space "description" ":" 1*any-char crlf
         / "%directive" space attribute-name ":" attribute-value crlf
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 Without parameters:
 C -directive
 S %directive directive:rwhois
 S %directive description:RWhois directive
 S %directive
 S %directive directive:quit
 S %directive description:Quit connection
 S %directive
 S %ok

Williamson, et. al. Informational [Page 23] RFC 2167 RWhois Protocol June 1997

 With parameters:
 C -directive quit
 S %directive directive:quit
 S %directive description:Quit connection
 S %directive
 S %ok

3.3.3 display

 Description
 By default, the server uses the dump format for the output of a query
 result. The output format can be changed with the "-display"
 directive.  When no parameter is given, the server must list all the
 display formats it supports. Every display record must end with an
 empty "%display" line.
 Currently, only the dump format is standard and must be supported by
 the server. Other output formats may be added in the future. See
 Section 3.4 for the definition of the dump format.
 ABNF
 display-dir = "-display" crlf
     / "-display" space display-name crlf
 display-name = 1*id-char
 display-response = *(display-record) response
 display-record = "%display" space "name" ":" display-name crlf
 *display-line "%display" crlf
 display-line = "%display" space attribute-name ":"
                attribute-value crlf
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 436 Invalid display format
 Examples
 # Get the available display formats.
 C -display
 S %display name:dump
 S %display
 S %ok

Williamson, et. al. Informational [Page 24] RFC 2167 RWhois Protocol June 1997

 # Change the active display format.
 C -display dump
 S %ok

3.3.4 forward

 Description
 The "-forward" directive instructs the server to follow all the
 referrals and return the results to the client. This directive can be
 used to run an RWhois server as a proxy server. The default value
 must be "off". When the value is set to "on", the server must not
 return referrals.
 ABNF
 forward-dir = "-forward" space on-off crlf
 forward-response = response
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -forward on
 S %ok
 C -forward off
 S %ok

3.3.5 holdconnect

 Description
 Normally, the server closes the connection after each query. This
 behavior is controlled by the holdconnect state, which can be changed
 with the "-holdconnect" directive. When the holdconnect state is set
 to "off", the server must close the connection after a query; when it
 is set to "on", the server must not close the connection after a
 query. By default, the holdconnect state must be set to "off" for
 each connection.

Williamson, et. al. Informational [Page 25] RFC 2167 RWhois Protocol June 1997

 ABNF
 holdconnect-dir = "-holdconnect" space on-off crlf
 holdconnect-response = response
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -holdconnect on
 S %ok
 C -holdconnect off
 S %ok

3.3.6 limit

 Description
 When returning a query result, the server should limit the number of
 objects returned to the client. The "-limit" directive changes this
 limit.  The default and maximum limit is server-dependent. The client
 can get the current limit by using the "-status" directive (see
 Section 3.3.13).
 ABNF
 limit-dir = "-limit" space 1*digit crlf
 limit-response = response
 Errors
 331 Invalid limit
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -limit 100
 S %ok

Williamson, et. al. Informational [Page 26] RFC 2167 RWhois Protocol June 1997

3.3.7 notify

 Description
 The "-notify" directive performs several functions.
  • If the server returns a referral that results in an error, the

client can report the bad referral to the server using the

      "badref" option.
    * When the client follows referrals and goes through the same
      referral twice, that referral is a recursive referral and causes
      a referral loop. The client can report the recursive referral to
      the server using the "recurref" option.
    * When the data in an authority area changes, a master server can
      use the "update" option to notify its slave servers to update
      the data.
    * The "inssec" option allows an RWhois server to register itself
      as a slave server for an authority area with a master server.
      The master server may reject the request on the basis of its
      registration policy.
    * The "delsec" option allows a slave server to cancel its
      registration with the master server.
 ABNF
 notify-dir = "-notify" space "badref" space referral-query crlf
         / "-notify" space "recurref" space referral-query crlf
    / "-notify" space "update" space host-port ":" authority-area crlf
         / "-notify" space "inssec" space host-port ":"
           authority-area crlf
         / "-notify" space "delsec" space host-port ":"
           authority-area crlf
 referral-query = referral-url space [class-name space] query
 notify-response = response
 See Section 3.4 for the definitions of referral-url and query.
 Errors
 338 Invalid directive syntax
 340 Invalid authority area
 342 Invalid host/port
 400 Directive not available
 401 Not authorized for directive

Williamson, et. al. Informational [Page 27] RFC 2167 RWhois Protocol June 1997

 Examples
 # The client reports a bad referral to rwhois.foobar.com to the
 # server.
 C -notify badref rwhois://rwhois.foobar.com:4321/auth-area=foobar.com
   domain foobar.com
 S %ok
 # The client reports a recursive referral to rwhois.foobar.com to the
 # server.
 C -notify recurref rwhois://rwhois.foobar.com:4321/auth-area=
   foobar.com contact Last-Name="Beeblebrox"
 S %ok
 # The master server for the foobar.com authority area notifies its
 # slave servers to update the data.
 C -notify update master.foobar.com:4321:foobar.com
 S %ok
 # The server rwhois2.foobar.com registers as a slave server for the
 # foobar.com authority area.
 C -notify inssec rwhois2.foobar.com:4321:foobar.com
 S %ok
 # The server rwhois2.foobar.com cancels its registration as a slave
 # server for the foobar.com authority area.
 C -notify delsec rwhois2.foobar.com:4321:foobar.com
 S %ok

3.3.8 quit

 Description
 The "-quit" directive can be used by the client to close the
 connection.  Before the server closes the connection, it must respond
 with "%ok".
 ABNF
 quit-dir = "-quit" crlf
 quit-response = response
 Errors
 No errors.

Williamson, et. al. Informational [Page 28] RFC 2167 RWhois Protocol June 1997

 Examples
 C -quit
 S %ok

3.3.9 register

 Description
 The "-register" directive can be used by the client to add, modify,
 or delete objects in the server's database. The client must wait to
 send the registration data until the "%ok" response is received from
 the server.  This directive has the following options.
  • The "add" option indicates that the object being sent should be

added to the server's database.

  • The "mod" option indicates that the object being sent is a

modification of an object that already resides on the server's

      database. During a modify operation, the "_NEW_" tag is used to
      delineate the end of the original (unmodified) object and the
      beginning of the replacement object. That is, the identifying
      characteristics of the original object are sent first, then the
      "_NEW_" separator is sent, and then the entire replacement
      object is sent.
    The "del" option indicates that the object being sent should be
    deleted from the server's database.
 After a register operation (add, modify, or delete an object) in an
 authority area, the server should update the "Serial-Number" variable
 in the SOA information for the authority area. This is useful for
 data replication because a slave server checks the "Serial-Number"
 variable to detect a data change at the master server (see Section
 3.6.2).
 ABNF
 register-dir = register-on space "add" space maintainer-id crlf
                register-add register-off
         / register-on space "mod" space maintainer-id crlf
           register-mod register-off
         / register-on space "del" space maintainer-id crlf
           register-del register-off
 register-on = "-register" space "on"
 register-off = "-register" space "off" crlf
 register-add = 1*(register-line crlf)
 register-mod = 1*(register-line crlf) "_NEW_" crlf
                1*(register-line crlf)
 register-del = 1*(register-line crlf)

Williamson, et. al. Informational [Page 29] RFC 2167 RWhois Protocol June 1997

 maintainer-id = email
 register-line = attribute-name ":" attribute-value
 register-on-response = response
 register-off-response = "%register" space "ID" ":" object-id crlf
                         response
         / "%register" space "Updated" ":" time-stamp crlf response
         / response
  • The server must return the register-on-response for the

"-register on" directive and the register-off-response for the

      "-register off" directive.
    * The maintainer-id identifies, for maintenance purposes, the
      sender of registration information. The server should not use it
      to authenticate the sender.
    * For the "add" option, the client must send all the required
      attributes for the object, including the Class-Name and Auth-
      Area attributes.  However, the client must not send the ID and
      Updated attributes. These attributes are assigned by the server
      and returned in the response.
    * For the "mod" option, the client must send the identifying
      information for the object to be modified, followed by the
      "_NEW_" separator and the entire replacement object. The
      identifying information must contain the ID and Updated
      attributes; it may contain other attributes, but the server may
      not check them. The ID, Auth-Area, and Class-Name attributes
      must match in both the original object data and the replacement
      object. The original object data is sent before the replacement
      object to enable the server to lock the record in the database.
    * For the "del" option, the client must send the identifying
      information for the object to be deleted. The identifying
      information must contain the ID and Updated attributes; it may
      contain other attributes, but the server may not check them.
 Errors
 120 Registration deferred
 320 Invalid attribute
 321 Invalid attribute syntax
 322 Required attribute missing
 323 Object reference not found
 324 Primary key not unique
 325 Failed to update outdated object
 336 Object not found
 338 Invalid directive syntax
 340 Invalid authority area
 341 Invalid class
 400 Directive not available
 401 Not authorized for directive

Williamson, et. al. Informational [Page 30] RFC 2167 RWhois Protocol June 1997

 Examples
 # Add an object.
 C -register on add joe@netsol.com
 S %ok
 C Class-Name:contact
 C Auth-Area:a.com
 C First-Name:Scott
 C Last-Name:Williamson
 C Name:Williamson, Scott
 C Email:scottw@a.com
 C -register off
 S %register ID:23456789.a.com
 S %register Updated:19961205224403000
 S %ok
 # Modify an object.
 C -register on mod joe@netsol.com
 S %ok
 C ID:23456789.a.com
 C Updated:19961205124403000
 C _NEW_
 C Class-Name:contact
 C Auth-Area:a.com
 C ID:23456789.a.com
 C First-Name:Scott
 C Last-Name:Williamson
 C Name:Williamson, Scott
 C Email:sw@a.com
 C -register off
 S %ok
 # Delete an object.
 C -register on del joe@netsol.com
 S %ok
 C ID:23456789.a.com
 C Updated:19961205224403000
 C -register off
 S %ok

3.3.10 schema

 Description
 The "-schema" directive can be used by the client to get the
 attribute definitions of one or more classes in an authority area. If
 the client specifies class names, the server must return the
 attribute definitions of the specified classes. Otherwise, the server

Williamson, et. al. Informational [Page 31] RFC 2167 RWhois Protocol June 1997

 must return the attribute definitions of all the classes in the
 authority area. Every schema record must end with an empty "%schema"
 line.
 ABNF
 schema-dir = "-schema" space authority-area *(space class-name) crlf
 schema-response = *schema-record response
 schema-record = *schema-line "%schema" crlf
 schema-line = "%schema" space class-name ":" attribute-name ":"
               attribute-value crlf
 Errors
 338 Invalid directive syntax
 340 Invalid authority area
 341 Invalid class
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -schema map
 S %schema map:attribute:Class-Name
 S %schema map:description:Type of the object
 S %schema map:type:TEXT
 S %schema map:format:re:[a-zA-Z0-9-]+
 S %schema map:indexed:OFF
 S %schema map:required:ON
 S %schema map:multi-line:OFF
 S %schema map:repeatable:OFF
 S %schema map:primary:OFF
 S %schema map:hierarchical:OFF
 S %schema map:private:OFF
 S %schema
 S %schema map:attribute:ID
 S %schema map:description:Globally unique object identifier
 S %schema map:type:TEXT
 S %schema map:format:re:[0-9]+.[a-zA-Z0-9.-]+

Williamson, et. al. Informational [Page 32] RFC 2167 RWhois Protocol June 1997

 S %schema map:indexed:ON
 S %schema map:required:ON
 S %schema map:multi-line:OFF
 S %schema map:repeatable:OFF
 S %schema map:primary:ON
 S %schema map:hierarchical:OFF
 S %schema map:private:OFF
 S %schema
 # This is an abbreviated example, more attributes usually follow.
 S %ok

3.3.11 security

 Description
 The "-security" directive enables either a client request or a server
 response to be authenticated and/or encrypted. Currently, RWhois uses
 two standard security methods: password and PGP. Password provides
 authentication only, and PGP provides both authentication and
 encryption.  This directive can be used to securely access or update
 any information (meta or data) in an authority area that is protected
 by one or more guardian objects.
 ABNF
 security-dir = "-security" space "on" space direction space
         security-method [space security-data] crlf
         security-payload ["-security" space "off" crlf]
 direction = "request" / "response"
 security-method = "password" / "pgp" / 1*id-char
 security-data = password-data / pgp-data / 1*any-char
 password-data = 1*any-char
 pgp-data = "signed" / "encrypt" [space key-id] / "signed-encrypt"
            [space key-id]
 security-payload = *(*any-char crlf)
 security-response = response
  • The "password" security-method is available in the "request"

direction only. For password, the security-data is a cleartext

      password.
    * The "pgp" security-method is available in both the "request" and
      "response" directions. For PGP, the security-data indicates how
      to treat the security-payload: signed, encrypted, or signed and
      encrypted. To encrypt the security-payload in the "response"
      direction, the security-data must include the public key ID with
      which to encrypt it.

Williamson, et. al. Informational [Page 33] RFC 2167 RWhois Protocol June 1997

 Errors
 338 Invalid directive syntax
 352 Invalid security method
 353 Authentication failed
 354 Encryption failed
 400 Directive not available
 401 Not authorized for directive
 Examples
 # Authenticate a request using password.
 C -security on request password hello!1
 S %ok
 # Authenticate a PGP signed request.
 C -security on request pgp signed
 S %ok
 C -register on mod joe@netsol.com
 S %ok
 C -----BEGIN PGP MESSAGE-----
 C Version: 2.6.2
 C
 C owHrZJjKzMpgdP9D9crUhdpBYnwHGRnPbmVhmHlV7Hef9je/n7vyzhmE6589/+Dg
 C jPpVm59tNz92vPSmrFB/4ankBRz+xgY+7z9OUYjefGahbWSNwzzxbw6TpWZGerU+
 C uOUg/Cygs33JBdHqjwEc+wyfZPp+N5p2bu+ywoaOu8eLPyn+m2Mt/T9p1UaG68vP
 C Zd2d9EPw+Ywpio7dco6yh3b/v7zmQxJHcWpyaVFmSSUDEHi6WBkZm5iamVtY6iXq
 C JefnKnCFFqQklqSmWBlaWpoZGhmYGhqZmBgYGxgYKHA55yQWF+v6JeamWiXn55Uk
 C JpcocDmWlmToOhalJlpB9cf7uYbHE6kWi/VumUXFJRB9wcn5JUBdPokwgfDMnJzM
 C xNzi/DwFLjQBHQWoatfcxMwcq+JyB6h5AA==
 C =a0sQ
 C -----END PGP MESSAGE-----
 C -register off
 S %ok
 # Encrypt a response using PGP. 52160EC1 is the public key ID with
 # which the response is encrypted.
 C -security on response pgp encrypt 52160EC1
 S %ok
 C -xfer com class=domain attribute=Domain-Name
   attribute=Organization-Name
 S -----BEGIN PGP MESSAGE-----
 S Version: 2.6.2
 S
 S hIwDqWWhK1IWDsEBBACOXssTzD2CbB7Vjj2cNURScpJc2as2TbUDOQiwkT+8qFgG
 S ZyRfktpwNNTawRIcGOk1Kcs84z8a3vvTA/oje9vZexHtzfJwBHFdiIZxPuCEpvgv
 S 2ppK7WqlmHGcQKVBJJHYw7Fq83CUkeGJB9P1M3CQiXeW8h8MwAuhxSgbgt23PKYA
 S AABuhknJrXeh9Owm81+MvyzgLOyM7sjDYmttU9sj/yuOYmAhS9V+34MT/Mwn4wO8

Williamson, et. al. Informational [Page 34] RFC 2167 RWhois Protocol June 1997

 S 2BCsJqBHXbwOuYKs02p0se4jyKFtZR8MDPWNm9QyAP+oNMTjsufy6ZRa9PegUC6t
 S HDhXymkiP03mKMMVK1//7X0=
 S =vZ2x
 S -----END PGP MESSAGE-----
 S %ok

3.3.12 soa

 Description
 The "-soa" directive can be used by the client to retrieve the SOA
 information for one or more authority areas. When no authority area
 name is given, the server must return the SOA information for all the
 authority areas. Every SOA record must end with an empty "%soa" line.
 ABNF
 soa-dir = "-soa" *(space authority-area) crlf
 soa-response = *soa-record response
 soa-record = *soa-line "%soa" crlf
 soa-line = "%soa" space "authority" ":" authority-area crlf
    / "%soa" space "ttl" ":" 1*digit crlf
    / "%soa" space "serial" ":" time-stamp crlf
    / "%soa" space "refresh" ":" 1*digit crlf
    / "%soa" space "increment" ":" 1*digit crlf
    / "%soa" space "retry" ":" 1*digit crlf
    / "%soa" space "tech-contact" ":" email crlf
    / "%soa" space "admin-contact" ":" email crlf
    / "%soa" space "hostmaster" ":" email crlf
    / "%soa" space "primary" ":" host-port crlf
    / "%soa" space attribute-name ":" attribute-value crlf
 The server must return the following SOA information for an authority
 area.

attribute-name attribute-value Comments

authority authority-area This is the name of the authority area.

ttl 1*digit This is the default time to live for

                               the data in the authority area.

serial time-stamp This is the serial number of the data

                               in the authority area; it changes
                               when the data changes.

Williamson, et. al. Informational [Page 35] RFC 2167 RWhois Protocol June 1997

refresh 1*digit This is the time interval before a

                               slave server checks for complete
                               replication.

increment 1*digit This is the time interval before a

                               slave server checks for incremental
                               replication.

retry 1*digit This is the time interval before a

                               slave server tries again to connect
                               to a master server that appears to be
                               out-of-service.

tech-contact email This is the contact for the operation

                               of the master server.

admin-contact email This is the contact for the data

                               integrity at the master server.

hostmaster email This is the contact for sending update

                               requests at the master server.

primary host-port This is the host name (or IP address)

                               and port number of the master server.
 Errors
 338 Invalid directive syntax
 340 Invalid authority area
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -soa org
 S %soa authority:org
 S %soa ttl:86400
 S %soa serial:19961119111535000
 S %soa refresh:3600
 S %soa increment:1800
 S %soa retry:180
 S %soa tech-contact:tech@internic.net
 S %soa admin-contact:admin@internic.net
 S %soa hostmaster:hostmaster@internic.net
 S %soa primary:rs.internic.net:4321
 S %soa
 S %ok

Williamson, et. al. Informational [Page 36] RFC 2167 RWhois Protocol June 1997

3.3.13 status

 Description
 The "-status" directive can be used by the client to get various
 status flags from the server. The response must include the number of
 objects in all the authority areas, the current display format, the
 server contact information, and the status flags for the state-
 oriented directives:  "-limit", "-holdconnect", and "-forward".
 ABNF
 status-dir = "-status" crlf
 status-response = *status-line response
 status-line = "%status" space "limit" ":" 1*digit crlf
    / "%status" space "holdconnect" ":" on-off crlf
    / "%status" space "forward" ":" on-off crlf
    / "%status" space "objects" ":" 1*digit crlf
    / "%status" space "display" ":" 1*any-char crlf
    / "%status" space "contact" ":" email crlf
    / "%status" space attribute-name ":" attribute-value crlf
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 C -status
 S %status limit:20
 S %status holdconnect:OFF
 S %status forward:OFF
 S %status objects:12345
 S %status display:dump
 S %status contact:joe@rwhois.net
 S %ok

3.3.14 xfer

 Description
 The "-xfer" directive can be used by the client (generally, a slave
 server) to transfer the data in an authority area. The client can
 control the amount of data transferred using one of the following
 options.

Williamson, et. al. Informational [Page 37] RFC 2167 RWhois Protocol June 1997

  • serial-number: The client can transfer all the objects that have

been added, modified or deleted since a certain time, specifying

      the serial-number that indicates that time. This option is used
      for incremental replication.
    * class: The client can limit the data transfer to one or more
      classes, using the "class=<class-name>" option. The server must
      return data for only the specified classes. If no class name is
      specified, the server must return data for all the classes.
    * attribute: The client can limit the data transfer to one or more
      attributes of a class, using the "attribute=<attribute-name>"
      option in combination with the "class=<class-name>" option. The
      server must return data for only the specified attributes of the
      class. The client can specify multiple "class=" and "attribute="
      pairs.
 ABNF
 xfer-dir = "-xfer" space authority-area *attribute-def
         [space serial-number] crlf
 attribute-def = [space "class=" class-name] *(space "attribute="
                 attribute-name)
 serial-number = time-stamp
 xfer-response = *xfer-record response
 xfer-record = *xfer-line "%xfer" crlf
 xfer-line = "%xfer" space class-name ":" attribute-name ":"
             attribute-value crlf
 Errors
 332 Nothing to transfer
 333 Not master for authority area
 338 Invalid directive syntax
 340 Invalid authority area
 341 Invalid class
 342 Invalid attribute
 400 Directive not available
 401 Not authorized for directive

Williamson, et. al. Informational [Page 38] RFC 2167 RWhois Protocol June 1997

 Examples
 C -xfer com class=domain attribute=Domain-Name
   attribute=Organization-Name
 S %xfer domain:Domain-Name:acme.com
 S %xfer domain:Organization-Name:Acme Inc.
 S %xfer
 S %xfer domain:Domain-Name:vogon.com
 S %xfer domain:Organization-Name:Vogon Heavy Industries
 S %xfer
 S %ok

3.3.15 X

 Description
 The "-X" directive is used to specify an additional, non-standard
 directive. It can be implemented by executing an external program, by
 internal functions, or by other means. It may interact with the
 client or simply produce output like one of the standard directives.
 ABNF
 x-dir = "-X-" x-directive [space x-arguments] crlf *x-line
 x-directive = 1*id-char
 x-arguments = *any-char
 x-response = *(*any-char crlf) response
 x-line = *any-char crlf
 Errors
 338 Invalid directive syntax
 400 Directive not available
 401 Not authorized for directive
 Examples
 The following example uses an implementation that executes an
 external program, the UNIX "date" command. The server runs the "date"
 command and returns its output to the client.
 C -X-date
 S Mon Jan 6 13:21:20 EST 1997
 S %ok

Williamson, et. al. Informational [Page 39] RFC 2167 RWhois Protocol June 1997

3.4 Query

 Description
 The query allows the client to retrieve objects from the server's
 database.  The server must support the following types of queries.
  • Unrestricted query: It is a single word or a quoted string. The

server must return all the matching objects where one or more

      attributes match the query, regardless of the class.
    * Class-restricted query: It is a class name specified in front
      of the unrestricted query. The server must return all the
      matching objects where one or more attributes of the specified
      class match the query.
    * Attribute-restricted query: It is of the
      "<attribute-name>=<search-string>" form. The server must return
      all the matching objects where the specified attribute matches
      the query.
 The server may implement the following types of queries.
  • Boolean operator query: It consists of simpler queries combined

using the "and" and "or" operators.

  • Wild card query: It consists of an asterisk ("*") in the front

and/or at the end of the search string. The server may support

      partial matching using the asterisk.
 In response to the query, the server will return the objects that
 match the query. If the server does not support complex queries,
 with, for example, wild cards or boolean operators, the server may
 return the "351 Query too complex" error. When the number of objects
 found exceeds the limit (set by the "-limit" directive), the server
 should return the objects, followed by the "330 Exceeded maximum
 objects limit" error.
 The default object output format is the dump format that uses the
 "<class-name>:<attribute-name>;<type character>:<attribute-value>"
 form.  The type character is optional and identifies the type of the
 attribute value. The type character is a shorthand for the Type field
 of the attribute definition (see Section 2.3.1). The type characters
 are defined as follows.

Williamson, et. al. Informational [Page 40] RFC 2167 RWhois Protocol June 1997

  Type          Attribute
  character     Type
  T             TEXT
  I             ID
  S             SEE-ALSO
 When no type character is given, the client should assume the "T"
 type character. The server must provide the type character when the
 attribute type is ID or SEE-ALSO. The purpose of the type character
 is to aid the client in displaying the data. For example, when an
 attribute value is an ID, the client may indicate to the end-user
 that it is possible to retrieve the object indicated by the ID.
 The server may return one or more referrals in the "%referral
 rwhois://<host-name>:<port-number>/auth-area=<authority area>" form.
 The client can distinguish multiple referrals by comparing their
 authority areas; if all the referrals refer to the same authority
 area, the client should follow only one of them. Otherwise, the
 client should follow all of them. To follow a referral, the client
 must connect to the specified host name and port number, and issue
 the same query.
 ABNF
 rwhois-query = [class-name space] query crlf
 query = query-string / attribute-query / query bin-boolean query
 query-char = <any-char, except """, space, tab>
 quoted-query-char = query-char / space / tab / "
 query-string = ["*"] 1*query-char ["*"] / """ ["*"]
         1*quoted-query-char ["*"] """
 attribute-query = attribute-name "=" query-string
 bin-boolean = "and" / "or"
 rwhois-query-result = *(query-record / referral-record) response
 query-record = 1*query-line crlf
 query-line = class-name ":" attribute-name [";" type-char] ":"
         attribute-value crlf
 type-char = "T" / "I" / "S"
 referral-record = 1*(referral-line crlf)
 referral-line = "%referral" space referral-url
 referral-url = "rwhois" ":" "//" host-port "/" "auth-area="
                authority-area

Williamson, et. al. Informational [Page 41] RFC 2167 RWhois Protocol June 1997

 Errors
 130 Object not authoritative
 230 No objects found
 330 Exceeded maximum objects limit
 340 Invalid authority area
 341 Invalid class
 342 Invalid attribute
 350 Invalid query syntax
 351 Query too complex
 Examples
 This example illustrates a query, where no objects are found.
 C vogon
 S %error 230 No objects found
 This example illustrates a query, where two different objects are
 returned.
 C ibm
 S domain:ID:IBMLIFEPRO-DOM.com
 S domain:Auth-Area:com
 S domain:Domain-Name:IBMLIFEPRO.COM
 S domain:Org-Name:IBM
 S domain:Server;I:NS12345-HST.NET
 S domain:Server;I:NS12345-HST.NET
 S domain:Admin-Contact;I:TW1234.COM
 S domain:Tech-Contact;I:BN123.NET
 S domain:Updated:19961120123455000
 S domain:Updated-By:autoreg@internic.net
 S domain:Class-Name:domain
 S
 S network:ID:NET-IBMNET-3.0.0.0/0
 S network:Auth-Area:0.0.0.0/0
 S network:Network-Name:IBMNET-3
 S network:IP-Network:123.45.67.0/24
 S network:Org-Name:IBM
 S network:Street-Address:1234 Maneck Avenue
 S network:City:Black Plains
 S network:State:NY
 S network:Postal-Code:12345
 S network:Country-Code:US
 S network:Tech-Contact;I:MG305.COM
 S network:Updated:19931120123455000
 S network:Updated-By:joeblo@nic.ddn.mil
 S network:Class-Name:network

Williamson, et. al. Informational [Page 42] RFC 2167 RWhois Protocol June 1997

 S
 S %ok
 This example illustrates a query with a class restrictor, where the
 number of objects found exceeds the limit set by the "-limit"
 directive.
 C -limit 1
 S %ok
 C domain ibm
 S domain:ID:IBMLIFEPRO-DOM.com
 S domain:Auth-Area:com
 S domain:Domain-Name:IBMLIFEPRO.COM
 S domain:Org-Name:IBM
 S domain:Server;I:NS12345-HST.NET
 S domain:Server;I:NS12345-HST.NET
 S domain:Admin-Contact;I:TW1234.COM
 S domain:Tech-Contact;I:BN123.NET
 S domain:Updated:19961120123455000
 S domain:Updated-By:erice@internic.net
 S domain:Class-Name:domain
 S
 S %error 330 Exceeded maximum objects limit
 This is an example of attribute matching.
 C domain Domain-Name=konabo.com
 S domain:ID:12345678.com
 S domain:Auth-Area:com
 S domain:Domain-Name:konabo.com
 S domain:Org-Name:ACME
 S domain:Server;I:12345670.com
 S domain:Server;I:12345671.com
 S domain:Admin-Contact;I:12345660.com
 S domain:Tech-Contact;I:12345665.com
 S domain:Updated:19961120123455000
 S domain:Updated-By:joeblo@internic.net
 S domain:Class-Name:domain
 S
 S %ok
 This example illustrates a link referral.
 C domain a.b.rwhois.net
 # The server returns a link referral to a server serving the
 # b.rwhois.net authority area.
 S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net
 S %ok

Williamson, et. al. Informational [Page 43] RFC 2167 RWhois Protocol June 1997

 This example illustrates a punt referral.
 C domain internic.net
 # The server returns a punt referral to a server serving the root
 # authority area.
 S %referral rwhois://rs.internic.net:4321/auth-area=.
 S %ok
 This example illustrates multiple referrals that refer to the same
 authority area. The client should follow only one of them.
 C domain a.b.rwhois.net
 # The server returns link referrals to two RWhois servers serving the
 # b.rwhois.net authority area.
 S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net
 S %referral rwhois://slave.b.rwhois.net:4321/auth-area=b.rwhois.net
 S %ok
 This example illustrates multiple referrals that refer to different
 authority areas. The client should follow all of them.
 C contact Last-Name="Beeblebrox"
 # The server returns a link referral to a server serving the
 # b.rwhois.net authority area.
 S %referral rwhois://master.b.rwhois.net:4321/auth-area=b.rwhois.net
 # The server also returns a punt referral to a server serving the
 # net authority area since the query matched an entry in the
 # non-hierarchical index received from it.
 S %referral rwhois://rs.internic.net:4321/auth-area=net
 S %ok

Williamson, et. al. Informational [Page 44] RFC 2167 RWhois Protocol June 1997

 This is an example of a boolean operator and wildcard matching.
 C ibm and jubliana*
 S host:ID:JUBLIANA-HST.root
 S host:Auth-Area:.
 S host:Host-Name:JUBLIANA.TRL.IBM.CO.JP
 S host:IP-Address:123.156.220.68
 S host:Org-Name:IBM
 S host:Street-Address:1234 Maneck Avenue
 S host:City:Black Plains
 S host:State:NY
 S host:Postal-Code:12345
 S host:Country-Code:US
 S host:Updated:19961120123455000
 S host:Updated-By:joeblo@nic.ddn.mil
 S host:Class-Name:host
 S
 S %ok

3.5 Connection Model

 An RWhois client can connect to an RWhois server using one of the
 following transport protocols.

3.5.1 Transmission Control Protocol (TCP)

 TCP provides a reliable stream transport service between a client and
 a server. In RWhois, TCP is the default transport protocol because,
 during a particular session, a client can send more than one query
 and a server can reliably return a large amount of data for each of
 those queries. By default, a TCP RWhois server should run on the
 standard, Internet Assigned Number Authority (IANA)-assigned port
 4321. However, if port 4321 is not available, it may run on an
 available port in the non-reserved range (1024 - 65535).

3.5.2 User Datagram Protocol (UDP)

 UDP provides an unreliable connectionless transport service between a
 client and a server. In RWhois, UDP may be used as the transport
 protocol if a client wants to quickly send only one query, without
 incurring the overhead of establishing a TCP connection with a
 server. By default, a UDP RWhois server should run on the standard,
 IANA-assigned port 4321. However, if port 4321 is not available, it
 may run on an available port in the non-reserved range (1024 -
 65535). A separate document will describe the use of UDP as the
 transport protocol in RWhois.

Williamson, et. al. Informational [Page 45] RFC 2167 RWhois Protocol June 1997

3.6 Data Replication

 This section discusses when and how a slave server should replicate
 data.  Further, it describes the server registration and location
 mechanisms.

3.6.1 When to Replicate Data

 The time when a slave server may replicate data for an authority area
 is determined by the SOA variables for that authority area. The
 possible times are the following.
  • When the "Refresh-Interval" expires, a slave server may

completely replicate data.

  • When the "Increment-Interval" expires, a slave server may

incrementally replicate data.

  • A slave server fails to connect to its master server to

replicate data. When the "Retry-Interval" expires, it tries

      again to replicate data.
    * When the data in an authority area is changed and its "Serial-
      Number" updated, a master server may notify its slave servers to
      immediately update the data. To notify about the data change,
      the master server should send the "-notify update <host-
      name>:<port-number>:<authority-area>" directive to its slave
      servers.

3.6.2 How to Replicate Data

 To replicate data, a slave server sends a series of directives to its
 master server and checks each response before sending the next
 directive.  The following sections describe the protocols for
 complete and incremental replication.
 Complete Replication
 The protocol between a master server and a slave server to completely
 replicate data for an authority area is as follows.
   1. The slave server should connect to the master server. If there
      is a connection error, the slave server should log an error and
      exit.
   2. The slave server should send the "-soa <authority-area>"
      directive to the master server and parse the SOA variables from
      the response. Let the "Serial-Number" variable in this response
      be called the "old-serial-number".

Williamson, et. al. Informational [Page 46] RFC 2167 RWhois Protocol June 1997

   3. The slave server should send the "-class <authority-area>"
      directive to the master server and parse the versions of all the
      classes from the response.
   4. The slave server should send the "-schema <authority-area>"
      directive to the master server and parse the definitions of all
      the classes from the response.
   5. The slave server should send the "-xfer <authority-area>"
      directive to the master server and parse the data objects from
      the response. The master server should return all the data
      objects, excluding the deleted ones, in the authority area. The
      slave server should index these data objects.
   6. When the "Refresh-Interval" expires, the slave server should
      to the master server. If there is a connection error, the slave
      server should try again after the "Retry-Interval".
   7. The slave server should send the "-soa <authority-area>"
      directive to the master server and parse the SOA variables from
      the response. Let the "Serial-Number" variable in this response
      be called the "new-serial-number". If the "new-serial-number" is
      not greater than the "old-serial-number", go back to step 6.
      Otherwise, it indicates a data change at the master server.
   8. The slave server should send the "-class <authority-area>"
      directive to the master server and parse the versions of all the
      classes from the response. If the version of any of the classes
      has changed, the slave server should send the "-schema
      <authority-area>" directive to the master server and parse the
      definitions of all the classes from the response.
   9. The slave server should send the "-xfer <authority-area>"
      directive the master server and parse the data objects from the
      response. The master server should return all the data objects,
      excluding the deleted ones, in the authority area. The slave
      server should index these data objects and seamlessly replace
      the old index with the new one. Further, it should assign the
      "new-serial-number" to the "old-serial-number".
   10. Go back to step 6.
 Note that the "-class", "-schema", and "-xfer" directives change when
 a slave server replicates data for only a subset of the schema for an
 authority area.
 In the following example, a slave server completely replicates data
 for all the classes in an authority area. The notation in the example
 uses a prefix to indicate from where the information is coming. An
 "M" indicates that the master server sends the data to the slave
 server. An "S" indicates that the slave server sends the data to the
 master server. The line is a comment when "#" is used. The space
 after the prefix is not part of the data. The example authority area
 is "rwhois.net".

Williamson, et. al. Informational [Page 47] RFC 2167 RWhois Protocol June 1997

 # The slave server connects to the master server.
 M %rwhois V-1.5:00ffff:00 master.rwhois.net
 S -soa rwhois.net
 M ...
 M %soa serial:19970103102258000
 M %soa refresh:3600
 M ...
 S -class rwhois.net
 # The master server returns the versions of all the classes in the
 # rwhois.net authority area.
 S -schema rwhois.net
 # The master server returns the definitions of all the classes in the
 # rwhois.net authority area.
 S -xfer rwhois.net
 # The master server returns all the data objects, excluding the
 # deleted ones, in the rwhois.net authority area. The slave server
 # indexes these data objects.
 # The refresh interval of 3600 seconds expires.
 S -soa rwhois.net
 M ...
 M %soa serial:19970103103258000
 M %soa refresh:3600
 M ...
 # The new serial number 19970103103258000 is greater than the old
 # serial number 19970103102258000. It indicates a data change at the
 # master server.
 S -class rwhois.net
 # The master server returns the versions of all the classes in the
 # rwhois.net authority area. If the version of any of the classes has
 # changed, the slave server logs an error and closes the connection.
 S -xfer rwhois.net
 # The master server returns all the data objects, excluding the
 # deleted ones, in the rwhois.net authority area. The slave server
 # indexes these data objects and seamlessly replaces the old index.
 # The refresh interval of 3600 seconds expires.
 S ...
 Incremental Replication
 The protocol between a master server and a slave server to
 incrementally replicate data for an authority area is as follows.
   1. The slave server should connect to the master server. If there
      is a connection error, the slave server should log an error and
      exit.

Williamson, et. al. Informational [Page 48] RFC 2167 RWhois Protocol June 1997

   2. The slave server should send the "-soa <authority-area>"
      directive to the master server and parse the SOA variables from
      the response. Let the "Serial-Number" variable in this response
      be called the "old-serial-number".
   3. The slave server should send the "-class <authority-area>"
      directive to the master server and parse the versions of all the
      classes from the response.
   4. The slave server should send the "-schema <authority-area>"
      directive to the master server and parse the definitions of all
      the classes from the response.
   5. The slave server should send the "-xfer <authority-area>"
      directive to the master server and parse the data objects from
      the response. The master server should return all the data
      objects, excluding the deleted ones, in the authority area. The
      slave server should index these data objects.
   6. When the "Increment-Interval" expires, the slave server should
      connect to the master server. If there is a connection error,
      the slave server should try again after the "Retry-Interval".
   7. The slave server should send the "-soa <authority-area>"
      directive to the master server and parse the SOA variables from
      the response. Let the "Serial-Number" variable in this response
      be called the "new-serial-number". If the "new-serial-number" is
      not greater than the "old-serial-number", go back to step 6.
      Otherwise, it indicates a data change at the master server.
   8. The slave server should send the "-class <authority-area>"
      directive to the master server and parse the versions of all the
      classes from the response. If the version of any of the classes
      has changed, the slave server should send the "-schema
      <authority-area>" directive to the master server and parse the
      definitions of all the classes from the response. The slave
      server should then send the "-xfer <authority-area>" directive
      to the master server and parse the data objects from the
      response. The master server should return all the data objects,
      excluding the deleted ones, in the authority area. The slave
      server should index these data objects and seamlessly replace
      the old index with the new one. Further, it should assign the
      "new-serial-number" to the "old-serial-number". If the version
      of any of the classes has changed, go back to step 6.
   9. The slave server should send the "-xfer <authority-area>
      <old-serial-number>" directive to the master server and parse
      the data objects from the response. The master server should
      return all the data objects in the authority area that have been
      inserted, updated, or deleted since the "old-serial-number". The
      slave server should index all the data again after purging stale
      data objects and seamlessly replace the old index with the new
      one. Further, it should assign the "new-serial-number" to the
      "old-serial-number".
   10. Go back to step 6.

Williamson, et. al. Informational [Page 49] RFC 2167 RWhois Protocol June 1997

 Note that the "-class", "-schema", and "-xfer" directives change when
 a slave server replicates data for only a subset of the schema for an
 authority area.
 In the following example, a slave server incrementally replicates
 data for all the classes in an authority area. The notation in the
 example uses a prefix to indicate from where the information is
 coming. An "M" indicates that the master server sends the data to the
 slave server. An "S" indicates the slave server sends the data to the
 master server. The line is a comment when "#" is used. The space
 after the prefix is not part of the data. The example authority area
 is "rwhois.net".
 # The slave server connects to the master server.
 M %rwhois V-1.5:00ffff:00 master.rwhois.net
 S -soa rwhois.net
 M ...
 M %soa serial:19970103102258000
 M %soa increment:1800
 M ...
 S -class rwhois.net
 # The master server returns the versions of all the classes in the
 # rwhois.net authority area.
 S -schema rwhois.net
 # The master server returns the definitions of all the classes in the
 # rwhois.net authority area.
 S -xfer rwhois.net
 # The master server returns all the data objects, excluding the
 # deleted ones, in the rwhois.net authority area. The slave server
 # indexes these data objects.
 # The increment interval of 1800 seconds expires.
 S -soa rwhois.net
 M ...
 M %soa serial:19970103103258000
 M %soa increment:1800
 M ...
 # The new serial number 19970103103258000 is greater than the old
 # serial number 19970103102258000. It indicates a data change at
 # the master server.
 S -class rwhois.net
 # The master server returns the versions of all the classes in the
 # rwhois.net authority area. If the version of any of the classes has
 # changed, the slave server logs an error and closes the connection.
 S -xfer rwhois.net 19970103102258000

Williamson, et. al. Informational [Page 50] RFC 2167 RWhois Protocol June 1997

 # The master server returns all the data objects in the rwhois.net
 # authority area that have been inserted, updated, or deleted since
 # 19970103102258000. The slave server indexes all the data again
 # after purging stale data objects and seamlessly replaces the old
 # index. The increment interval of 1800 seconds expires.
 S ...

3.6.3 Server Registration

 This section discusses how an RWhois server can register itself or
 cancel its registration as a slave server for an authority area with
 a master server.
 The initial list of slave servers for an authority area should be
 manually configured at the master server. To register itself as a
 slave server, the server should send the "-notify inssec <host-
 name>:<port-number>:<authority-area>" directive to the master server.
 The master server may reject the request on the basis of its
 registration policy. To cancel its registration as a slave server,
 the server should send the "-notify delsec <host-name>:<port-
 number>:<authority-area>" directive to the master server. Note that
 the "host-name" and "port-number" in the above directives correspond
 to the requesting server.

3.6.4 Server Location

 To resolve a query in a particular authority area, an RWhois client
 may need to first locate the master and slave servers for that
 authority area.  The different server location mechanisms are as
 follows.
 Referrals
 An RWhois client should know about at least one RWhois server. It
 should send the "referral <authority-area>" query to that server. The
 query may be routed up or down the RWhois tree before getting
 resolved. If the query does get resolved, the result should be a
 referral object for that authority area. The client should parse the
 "Referral" attributes from the result to obtain a list of servers
 serving that authority area.
 The client should then send the "-soa <authority-area>" directive to
 one of the above servers and parse the "Primary-Server" variable from
 the response. The value of this variable is the master server. Then,
 the remaining servers in the list are the slave servers.

Williamson, et. al. Informational [Page 51] RFC 2167 RWhois Protocol June 1997

 SRV RRs
 The Server Resource Record (SRV RR), defined for DNS, can be used to
 locate the master and slave servers for an authority area. An SRV RR
 specifies the location of a network service in an organization's DNS.
 It is defined in [RFC 2052] as follows.
 Service.Proto.Name TTL Class SRV Priority Weight Port Target
 Since an authority area identifier is generally a domain name or an
 IP address, the RWhois SRV RRs can be added to the DNS file for that
 domain or IP address. For example, the RWhois SRV RRs for the
 "rwhois.net" authority area could be:
 rwhois.tcp.rwhois.net. 86400 IN SRV 10 0 4321 master.rwhois.net.
                                 SRV 20 0 4322 slave.rwhois.net.
 where the "master.rwhois.net" server has a higher priority than the
 "slave.rwhois.net" server. The client must try to connect to the
 server with a higher (lower-numbered) priority.

4. Security Considerations

 RWhois provides security using the guardian class (see Section
 2.3.6). Any information (meta or data) in an authority area can be
 guarded by containing pointers to one or more guardian objects; that
 is, it can be securely updated and accessed. Currently, there are two
 standard security methods: password and PGP (see Section 3.3.11).
 Password provides authentication only, and PGP provides both
 authentication and encryption.  PGP is the recommended security
 method in RWhois.
 The following sections discuss how to securely update and access the
 data in an authority area.

4.1 Data Update

 This involves the ability to securely add, modify, or delete some
 information (meta or data) in an authority area. An authority area,
 on the whole, can be guarded by linking guardians to its SOA and
 schema information. Only these guardians should be allowed to add
 objects to the authority area and modify its SOA and schema
 information. In addition, they can also modify or delete existing
 objects in the authority area. However, the function of modifying or
 deleting existing objects can be delegated to other guardians by
 linking them to objects on a per-object basis.

Williamson, et. al. Informational [Page 52] RFC 2167 RWhois Protocol June 1997

4.2 Access Control

 There are two access control issues; the first is the ability to
 securely transfer data between the slave and master servers. To
 transfer data for an authority area, a slave server can authenticate
 itself by satisfying one of the guardians linked to the SOA
 information of the authority area at the master server. In addition,
 the master server may encrypt the transferred data.
 The second issue is the ability to make public only a subset of the
 data in an authority area. If all the objects of a particular class
 need to be private, the Private attribute of the class should be set
 to true. If only some attributes of all the objects of a particular
 class need to be private, the Private attribute property of each of
 those attributes should be set to true. The guardians of such objects
 must be able to view them completely.

5. Acknowledgments

 The authors would like to acknowledge the following individuals.
 Stan Borinski
 C. Ming Lu
 Leslie Meador
 Michael Mealling
 Greg Pierce
 Amar Rao

6. References

 [CIP] Allen, J., "The Common Indexing Protocol (CIP)", Bunyip
 Information Systems, November 1996, Work in Progress.
 [Guardian] Singh, J., M. Kosters, "The InterNIC Guardian Object",
 ftp://rs.internic.net/policy/internic/internic-gen-1.txt, Network
 Solutions, February 1996.
 [RFC 821] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC
 821, ISI, August 1982.
 [RFC 822] Crocker, D, "Standards for the Format of ARPA Internet Text
 Messages", STD 11, RFC 822, University of Delaware, August 1982.
 [RFC 954] Harrenstien, K., Stahl, M., Feinler, E., "NICNAME/WHOIS",
 RFC 954, SRI, October 1985.
 [RFC 1034] Mockapetris, P. V., "Domain names - concepts and
 facilities", STD 13, RFC 1034, November 1987.

Williamson, et. al. Informational [Page 53] RFC 2167 RWhois Protocol June 1997

 [RFC 1714] Williamson, S., Kosters, M., "Referral Whois Protocol",
 RFC 1714, Network Solutions, November 1994.
 [RFC 1738] T. Berners-Lee, L. Masinter, M. McCahill, "Uniform
 Resource Locators (URL)", RFC 1738, CERN, Xerox Corporation,
 University of Minnesota, December 1994.
 [RFC 1991] Atkins, D.,  W. Stallings, P. Zimmermann, "PGP Message
 Exchange Formats", RFC 1991, MIT, Comp-Comm Consulting, Boulder
 Software Engineering, August 1996.
 [RFC 2052] Gulbrandsen, A., P. Vixie, "A DNS RR for specifying the
 location of services (DNS SRV)", RFC 2052, Troll Technologies, Vixie
 Enterprises, October 1996.
 [X.500] "The Directory: Overview of Concepts, Models and Service",
 CCITT Recommendation X.500, 1988.

Authors' Addresses

 Scott Williamson (scottw@rwhois.net)
 Mark Kosters (markk@internic.net)
 David Blacka (davidb@rwhois.net)
 Jasdip Singh (jasdips@rwhois.net)
 Koert Zeilstra (kzeil@rwhois.net)
 Postal Address:
 505 Huntmar Park Drive
 Herndon, VA 22070-5100
 Telephone: 703-742-0400

Williamson, et. al. Informational [Page 54] RFC 2167 RWhois Protocol June 1997

 Appendix A: Glossary Of Terms
 ABNF: Augmented Backus-Naur Form. Refined version of BNF, defined in
 [RFC 822]. See BNF.
 Attribute: A named field and the smallest typed unit in a database
 schema.  See Database Schema.
 Authority Area: An autonomous part of an RWhois tree. It is
 associated and named after a particular piece of a hierarchy and is
 able to state authoritatively whether or not an instance of
 hierarchical data is present within the RWhois tree. See RWhois Tree.
 Banner: A line sent by a server indicating which protocol versions it
 supports and which directives are implemented. This line is issued by
 the server after a connection is opened and as a response to the "-
 rwhois" directive. See Directive and Response.
 Base Class: A class from which all defined classes in a database
 schema inherit attributes. See Attribute, Class, and Database Schema.
 BNF: Backus-Naur Form. Language to precisely define the syntax of
 protocols and computer languages.
 Class: A collection of attributes. See Attribute.
 Complete Replication: The process of replicating all of the data for
 an authority area. See Replication.
 Database Schema: A collection of all the classes forming an RWhois
 database. See Class.
 Directive: A command that a client sends to a server to set a control
 parameter for the session, get the meta-information (class
 definitions and SOA information) about an authority area, or get the
 data in an authority area. See Class and SOA.
 Guardian Class: A standard class that contains security information.
 An object is guarded by containing a pointer to a guardian object.
 See Class and Object.
 Incremental Replication: The process of replicating the data that has
 changed since the last replication for an authority area. See
 Replication.
 Info: The miscellaneous information that a server sends to a client.

Williamson, et. al. Informational [Page 55] RFC 2167 RWhois Protocol June 1997

 Lexically Hierarchical Label: A text string whose position in a
 hierarchy is encoded in the string itself.
 Link Referral: A pointer to another server that is further down an
 RWhois tree. It is used to route a query down the tree. See Referral
 and RWhois Tree.
 Master Server: A server where the data is registered for an authority
 area.  It answers authoritatively to queries in the authority area.
 It is also called a primary server. See Authority Area.
 Namespace: A particular naming system defined by a set of rules
 describing the format of a name. Alternately, all of the names
 satisfying the rules.
 Object: An instance of a class. It is data with a type of <class>.
 See Class.
 PGP: Pretty Good Privacy. An authentication and encryption scheme.
 Primary Server: See Master Server.
 Punt Referral: A pointer to another server that is further up an
 RWhois tree. It is used to route a query up the tree. See Referral
 and RWhois Tree.
 Query: A command that a client sends to a server to access the data
 in an authority area.
 Query Routing: Redirecting a query to another server for resolution.
 See Query.
 Referral: A pointer to another server that is presumed to be closer
 to the desired data. It is used to route a query. See Query Routing.
 Referral Class: A standard class that contains referral information
 for an authority area. See Class and Referral.
 Replication: A server duplicating data from another server on a per-
 authority area basis. See Authority Area.
 Response: The information that a server returns to a client for a
 directive. See Directive.
 Result: The information that a server returns to a client for a
 query. It can be either the accessed data or referrals to other
 servers. See Query and Referral.

Williamson, et. al. Informational [Page 56] RFC 2167 RWhois Protocol June 1997

 RWhois Tree: A data information tree of RWhois servers where the data
 is arranged hierarchically in the authority areas. See Authority
 Area.
 Schema: See Class.
 Secondary Server: See Slave Server.
 Slave Server: A server where the data is replicated from the master
 server for an authority area. It also answers authoritatively to
 queries in the authority area. It is also called a secondary server.
 See Master Server.
 SOA: Start Of Authority. Administrative variables, defined at the
 master server, to control replication for an authority area. See
 Master Server and Replication.

Appendix B: RWhois ABNF

 This specification uses the Augmented Backus-Naur Form (ABNF)
 notation, as defined in Section 2 of [RFC 822].
 General Definitions
 Lexical Tokens
 alpha = "a".."z" / "A".."Z"
 digit = "0".."9"
 hex-digit = digit / "a".."f" / "A".. "F"
 id-char = alpha / digit / "_" / "-"
 any-char = <ASCII 1..255,
            except LF (linefeed) and CR (carriage return)>
 dns-char = alpha / digit / "-"
 email-char = <see [RFC 822]>
 space = " "
 tab = <ASCII TAB (tab)>
 lf = <ASCII LF (linefeed)>
 cr = <ASCII CR (carriage return)>
 crlf = cr lf
 Grammar
 year = 4digit
 month = 2digit
 day = 2digit
 hour = 2digit
 minute = 2digit
 second = 2digit

Williamson, et. al. Informational [Page 57] RFC 2167 RWhois Protocol June 1997

 milli-second = 3digit
 host-name = dns-char *(dns-char / ".")
 email = 1*email-char "@" host-name
 authority-area = (dns-char / ".") *(dns-char / "." / "/")
 object-id = 1*id-char "." authority-area
 host-port = (host-name / ip-address) ":" 1*5digit
 ip-address = 1*3digit "." 1*3digit "." 1*3digit "." 1*3digit
 class-name = 1*id-char
 attribute-name = 1*id-char
 attribute-value = 1*any-char
 time-stamp = year month day hour minute second milli-second
 on-off = "on" / "off"
 Note that the time-stamp must be in the Greenwich Mean Time (GMT)
 time zone.
 response = ok-response crlf / error-response crlf / info-response
 ok-response = "%ok"
 error-response = "%error" space error-code space error-text
 error-code = 3digit
 error-text = 1*any-char
 info-response = "%info" space "on" crlf *(*any-char crlf) "%info"
         space "off" crlf
 rwhois-banner = "%rwhois" space version-list space host-name
         [space implementation] crlf
 version-list = version *("," version)
 version = version-number [":" capability-id]
         / "V-1.5" ":" capability-id
 version-number = "V-" 1*digit "." 1*digit
 capability-id = response-id ":" extra-id
 response-id = 6hex-digit
 extra-id = 2hex-digit
 implementation = 1*any-char
 rwhois-protocol = client-sends / server-returns
 client-sends = *(directives / rwhois-query)
 server-returns = *(responses / rwhois-query-result)
 directives = rwhois-dir / class-dir / directive-dir / display-dir /
         holdconnect-dir / limit-dir / notify-dir / quit-dir /
         register-dir / schema-dir / security-dir / soa-dir /
         status-dir / xfer-dir / x-dir

Williamson, et. al. Informational [Page 58] RFC 2167 RWhois Protocol June 1997

 responses = rwhois-response / class-response/ directive-response/
         display-response/ holdconnect-response/ limit-response/
         notify-response/ quit-response/ register-response/
         schema-response / security-response/ soa-response/
         status-response/ xfer-response/ x-response
 Required Directives
 rwhois
 rwhois-dir = "-rwhois" space version-number [space implementation]
              crlf
 rwhois-response = "%rwhois" space version space host-name
         [space implementation] crlf
 Optional Directives
 class
 class-dir = "-class" space authority-area *(space class-name) crlf
 class-response = *class-record response
 class-record = *class-line "%class" crlf
 class-line = "%class" space class-name ":" "description" ":"
              1*any-char crlf
    / "%class" space class-name ":" "version" ":" time-stamp crlf
    / "%class" space class-name ":" meta-field ":" meta-value crlf
 meta-field = 1*id-char
 meta-value = 1*any-char
 directive
 directive-dir = "-directive" *(space directive-name)crlf
 directive-name = 1*id-char
 directive-response = *directive-record response
 directive-record = "%directive" space "directive" ":"
         directive-name crlf *directive-line "%directive" crlf
 directive-line = "%directive" space "description" ":" 1*any-char crlf
         / "%directive" space attribute-name ":" attribute-value crlf

Williamson, et. al. Informational [Page 59] RFC 2167 RWhois Protocol June 1997

 display
 display-dir = "-display" crlf
    / "-display" space display-name crlf
 display-name = 1*id-char
 display-response = *display-record response
 display-record = "%display" space "name" ":" display-name crlf
 *display-line "%display" crlf
 display-line = "%display" space attribute-name ":" attribute-value
                crlf
 holdconnect
 holdconnect-dir = "-holdconnect" space on-off crlf
 holdconnect-response = response
 limit
 limit-dir = "-limit" space 1*digit crlf
 limit-response = response
 notify
 notify-dir = "-notify" space "badref" space referral-query crlf
         / "-notify" space "recurref" space referral-query crlf
         / "-notify" space "update" space host-port ":" authority-area
           crlf
         / "-notify" space "inssec" space host-port ":" authority-area
           crlf
         / "-notify" space "delsec" space host-port ":" authority-area
           crlf
 referral-query = referral-url space [class-name space] query
 notify-response = response
 See the query section for the definitions of referral-url and query.
 quit
 quit-dir = "-quit" crlf
 quit-response = response

Williamson, et. al. Informational [Page 60] RFC 2167 RWhois Protocol June 1997

 register
 register-dir = register-on space "add" space maintainer-id crlf
         register-add register-off
         / register-on space "mod" space maintainer-id crlf
                 register-mod register-off
         / register-on space "del" space maintainer-id crlf
                 register-del register-off
 register-on = "-register" space "on"
 register-off = "-register" space "off" crlf
 register-add = 1*(register-line crlf)
 register-mod = 1*(register-line crlf) "_NEW_" crlf
                1*(register-line crlf)
 register-del = 1*(register-line crlf)
 maintainer-id = email
 register-line = attribute-name ":" attribute-value
 register-on-response = response
 register-off-response = "%register" space "ID" ":" object-id crlf
                         response
         / "%register" space "Updated" ":" time-stamp crlf response
         / response
 schema
 schema-dir = "-schema" space authority-area *(space class-name) crlf
 schema-response = *schema-record response
 schema-record = *schema-line "%schema" crlf
 schema-line = "%schema" space class-name ":" attribute-name ":"
         attribute-value crlf
 security
 security-dir = "-security" space "on" space direction space
         security-method [space security-data] crlf security-payload
         ["-security" space "off" crlf]
 direction = "request" / "response"
 security-method = "password" / "pgp" / 1*id-char
 security-data = password-data / pgp-data / 1*any-char
 password-data = 1*any-char
 pgp-data = "signed" / "encrypt" [space key-id] / "signed-encrypt"
            [space key-id]
 security-payload = *(*any-char crlf)
 security-response = response

Williamson, et. al. Informational [Page 61] RFC 2167 RWhois Protocol June 1997

 soa
 soa-dir = "-soa" *(space authority-area) crlf
 soa-response = *soa-record response
 soa-record = *soa-line "%soa" crlf
 soa-line = "%soa" space "authority" ":" authority-area crlf
    / "%soa" space "ttl" ":" 1*digit crlf
    / "%soa" space "serial" ":" time-stamp crlf
    / "%soa" space "refresh" ":" 1*digit crlf
    / "%soa" space "increment" ":" 1*digit crlf
    / "%soa" space "retry" ":" 1*digit crlf
    / "%soa" space "tech-contact" ":" email crlf
    / "%soa" space "admin-contact" ":" email crlf
    / "%soa" space "hostmaster" ":" email crlf
    / "%soa" space "primary" ":" host-port crlf
    / "%soa" space attribute-name ":" attribute-value crlf
 status
 status-dir = "-status" crlf
 status-response = *status-line response
 status-line = "%status" space "limit" ":" 1*digit crlf
    / "%status" space "holdconnect" ":" on-off crlf
    / "%status" space "forward" ":" on-off crlf
    / "%status" space "authority" ":" 1*digit crlf
    / "%status" space "display" ":" 1*any-char crlf
    / "%status" space "contact" ":" email crlf
    / "%status" space attribute-name ":" attribute-value crlf
 xfer
 xfer-dir = "-xfer" space authority-area *attribute-def
         [space serial-number] crlf
 attribute-def = [space "class=" class-name]
                 *(space "attribute=" attribute-name)
 serial-number = time-stamp
 xfer-response = *xfer-record response
 xfer-record = *xfer-line "%xfer" crlf
 xfer-line = "%xfer" space class-name ":" attribute-name ":"
             attribute-value crlf
 X
 x-dir = "-X-" x-directive [space *[x-arguments]] crlf
 x-directive = 1*id-char
 x-arguments = *any-char
 x-response = *(*any-char crlf) response

Williamson, et. al. Informational [Page 62] RFC 2167 RWhois Protocol June 1997

 Query
 rwhois-query = [class-name space] query crlf
 query = query-string / attribute-query / query bin-boolean query
 query-char = <any-char, except """, space, tab>
 quoted-query-char = query-char / space / tab / "
 query-string = 1*query-char ["*"] / """ 1*quoted-query-char ["*"] """
 attribute-query = attribute-name "=" query-string
 bin-boolean = "and" / "or"
 rwhois-query-result = *(query-record / referral-record) response
 query-record = 1*query-line crlf
 query-line = class-name ":" attribute-name [";" type-char] ":"
         attribute-value crlf
 type-char = "T" / "I" / "S"
 referral-record = 1*(referral-line crlf)
 referral-line = "%referral" space referral-url
 referral-url = "rwhois" ":" "//" host-port "/" "auth-area="
                authority-area

Appendix C: Error Codes

 When a server fails to run a command (directive or query), it returns
 an error response. The ABNF for an error response is as follows.
 error-response = "%error" space error-code space error-text
 error-code = 3digit
 error-text = 1*any-char
 An error text may be modified, but its meaning must remain the same.
 The server may append additional information to it, for example
 "%error 333 Not master for authority area: foobar.com".

Williamson, et. al. Informational [Page 63] RFC 2167 RWhois Protocol June 1997

 The following table describes the possible digits in the first,
 second, and third positions of an error code.
  XXX    Description
  1XX    Information only, no action required
  2XX    Information, action required
  3XX    Specific command error, retry that command or try another one
  4XX    Serious for current command, may correct with another command
  5XX    Fatal, must disconnect
  X0X    System wide, no specific command
  X1X    System wide, no specific command
  X2X    Registration error
  X3X    Specific command
  X4X    Specific command
  X5X    Specific command
  X6X    Extended message (version specific)
  XXX    Sequential order
 The following table gives an ordered list of RWhois error codes.
 These codes may be extended with implementation- specific codes. An
 implementation- specific code must have a "6" in the second position.
  Code    Text
  120     Registration deferred
  130     Object not authoritative
  230     No objects found
  300     Not compatible with version
  320     Invalid attribute
  321     Invalid attribute syntax
  322     Required attribute missing
  323     Object reference not found
  324     Primary key not unique
  325     Failed to update outdated object
  330     Exceeded maximum objects limit
  331     Invalid limit
  332     Nothing to transfer
  333     Not master for authority area
  336     Object not found
  338     Invalid directive syntax
  340     Invalid authority area
  341     Invalid class
  342     Invalid host/port
  350     Invalid query syntax
  351     Query too complex
  352     Invalid security method
  353     Authentication failed
  354     Encryption failed
  400     Directive not available
  401     Not authorized for directive

Williamson, et. al. Informational [Page 64] RFC 2167 RWhois Protocol June 1997

  402     Unidentified error
  420     Registration not authorized
  436     Invalid display format
  500     Memory allocation problem
  501     Service not available
  502     Unrecoverable error
  503     Idle time exceeded
 The following error codes, defined in [RFC 1714], have been made
 obsolete:  100, 200, 231, 334, 335, 337, 421, 431, 432, 433, 434,
 460, 461, and 530.

Appendix D: Capability ID

 The capability ID encodes which directives are implemented in the
 server.  To create a capability ID, perform a logical OR on all the
 hexadecimal numbers corresponding to the implemented directives. The
 resulting number is used in the banner, which is sent by the server
 after opening a connection and as a response to the "-rwhois"
 directive. The eight most significant bits of the capability ID are
 reserved for future use:
  class        000001h
  directive    000002h
  display      000004h
  forward      000008h
  holdconnect  000010h
  limit        000020h
  notify       000040h
  quit         000080h
  register     000100h
  schema       000200h
  security     000400h
  soa          000800h
  status       001000h
  xfer         002000h
  X            004000h

Williamson, et. al. Informational [Page 65] RFC 2167 RWhois Protocol June 1997

Appendix E: Schema Definitions

Attribute Definition Model

Name Type Description

Attribute N This is the name of the attribute.

Description S This is a free-form description of the attribute.

Type T This is a parameter that broadly indicates the use

                  of the attribute to the protocol. There are three
                  standard types: TEXT, ID, and SEE-ALSO. The default
                  is TEXT, which indicates that the value is a text
                  string.  ID indicates that the attribute contains
                  the ID of another RWhois object. This type of
                  attribute is used for database normalization. SEE-
                  ALSO indicates that the attribute contains a pointer
                  (a Uniform Resource Identifier (URI)) to some other
                  kind of external data; for example, a World Wide Web
                  page or FTP site.

Format S This is an interpretable string that describes the

                  acceptance format of the value. The server (and
                  optionally the client) should match the value to the
                  format string to determine if the value is
                  acceptable.  The format of this property is a
                  keyword indicating the syntax of the format string,
                  followed by a colon, followed by the format string
                  itself. Currently, the only keyword recognized is
                  "re" for POSIX.2 extended regular expressions.

Indexed B This is a true or false flag that indicates that

                  this attribute should be indexed (and therefore able
                  to be searched).

Required B This is a true or false flag that indicates that

                  this attribute must have a value.

Multi-Line B This is a true or false flag that indicates that

                  this attribute may have multiple instances in an
                  object; all the instances are to be considered as
                  multiple lines of the same attribute instance.

Williamson, et. al. Informational [Page 66] RFC 2167 RWhois Protocol June 1997

Repeatable B This is a true or false flag that indicates that

                  there may be multiple instances of this attribute in
                  a class and each instance is to be interpreted as a
                  separate instance (in contrast to Multi-Line). This
                  flag is mutually exclusive with Multi-Line: if
                  Multi-Line is true, then Repeatable must be false
                  and vice versa.

Primary B This is a true or false flag that indicates that

                  this attribute is a primary key. If more than one
                  attribute in a class is marked as primary, then
                  these attributes together form a single primary key.
                  The primary key is intended to be used to force
                  uniqueness among class instances. Therefore, there
                  can be only one instance of a primary key in a
                  database. The Primary flag implies that the
                  attribute is also required.

Hierarchical B This is a true or false flag that indicates that

                  this attribute is lexically hierarchical.

Private B This is a true or false flag that indicates whether

                  or not this attribute is private (that is, publicly
                  not viewable). It defaults to false. If it is true,
                  then only the clients that satisfy the
                  authentication/encryption requirements of a guardian
                  are able to view the attribute-value pair.

Williamson, et. al. Informational [Page 67] RFC 2167 RWhois Protocol June 1997

 Type is defined as follows:
  Type  ABNF Definition
   B     "ON" / "OFF"
   N     1*id-char
   S     1*any-char
   T     "ID" / "SEE-ALSO" / "TEXT"
 Base Class

Name Type Required RepeatableDescription

Class-Name TEXT Y N This attribute is the name of the

                                     class to which the object
                                     belongs.

Auth-Area TEXT Y N This attribute is the name of the

                                     authority area to which the
                                     object belongs.

ID TEXT Y N This attribute is the universal

                                     identifier of the object.

Updated TEXT Y N This attribute is a time/date

                                     stamp that indicates the time of
                                     last modification of the object.

Guardian ID N Y This attribute is a link to a

                                     guardian object. Its value is the
                                     ID of a guardian object.

Private TEXT N N This attribute is a true or false

                                     flag that indicates whether or
                                     not an object is private (that
                                     is, publicly not viewable). It
                                     defaults to false. If it is
                                     true, then only the clients
                                     that satisfy the
                                     authentication/encryption
                                     requirements of one of the
                                     object's guardians are able to
                                     view the object. If the object
                                     is publicly viewable, then the
                                     Private attribute property of
                                     each of its attributes still
                                     applies.

Williamson, et. al. Informational [Page 68] RFC 2167 RWhois Protocol June 1997

TTL TEXT N N This attribute is the

                                     "time-to-live" of a given object.
                                     It is included only if an object
                                     has a different time-to-live than
                                     the default given in the Start of
                                     Authority information. Its value
                                     is specified in seconds.

Appendix F: Changes RWhois V1.0 - V1.5

 General
  • Multiple authority areas per server.
  • Data replication.
  • Revised schema model.
  • Revised query routing rules.
  • Revised error codes.
  • Removed unnecessary spaces in responses and results.
 Directives
  • Class: New. Returns meta-information for a class.
  • Display: Can return supported display formats.
  • Load: Obsolete.
  • Notify: Syntax change.
  • Private: Obsolete.
  • Register: Syntax change.
  • Schema: Syntax change.
  • Security: Obsoletes Private.
  • Xfer: Syntax change.
 Query
  • Display option removed.
  • Output format: Only the dump format is standard; optional type

character added.

  • Attribute-restricted query.
  • Revised referral syntax.

Williamson, et. al. Informational [Page 69]

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