URI Scheme for SNMP                 May 2004
   
   
      Network Working Group                                        D.Black
      Internet Draft                                       EMC Corporation
      Document: draft-black-snmp-uri-05.txt                  K. McCloghrie
      Expires: November 2004                                 Cisco Systems
                                                          J. Schoenwaelder
                                           International University Bremen
                                                                  May 2004
   
   
               Uniform Resource Identifier (URI) Scheme for the
                  Simple Network Management Protocol (SNMP)
   
   
   Status of this Memo
   
      This document is an Internet-Draft and is subject to all
      provisions of Section 10 of RFC 2026.
   
      Internet-Drafts are working documents of the Internet Engineering
      Task Force (IETF), its areas, and its working groups.  Note that
      other groups may also distribute working documents as Internet-
      Drafts.
   
      Internet-Drafts are draft documents valid for a maximum of six
      months and may be updated, replaced, or obsoleted by other
      documents at any time.  It is inappropriate to use Internet-Drafts
      as reference material or to cite them other than as "work in
      progress."
   
      The list of current Internet-Drafts can be accessed at
           http://www.ietf.org/ietf/1id-abstracts.txt
      The list of Internet-Draft Shadow Directories can be accessed at
           http://www.ietf.org/shadow.html.
   
    Abstract
   
      SNMP and the Internet-Standard Management Framework are widely
      used for management of communication devices, creating needs to
      specify SNMP access (including access to SNMP MIB object
      instances) from non-SNMP management environments.  For example,
      when out-of-band IP management is used via a separate management
      interface (e.g., for a device that does not support in-band IP
      access) there is a need for a uniform way to indicate how to
      contact the device for management.  URIs fit this need well, as
      they allow a single text string to indicate a management access
      communication endpoint for a wide variety of IP-based protocols.
      This document defines a URI scheme so that SNMP can be designated
      as the protocol used for management.  The scheme also allows a URI
      to designate one or more MIB object instances.
   
   
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                            URI Scheme for SNMP                 May 2004
   
   
   Conventions used in this document
   
      The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
      NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
      in this document are to be interpreted as described in [RFC 2119].
   
   Table of Contents
   
      1. Introduction...................................................2
      2. Syntax of an SNMP URI..........................................3
         2.1 Relative URI Considerations................................4
      3. Semantics and Operations.......................................4
         3.1 SNMP Service URIs..........................................4
         3.2 SNMP Object URIs...........................................5
         3.3 OID Groups in SNMP URIs....................................8
         3.4 Interoperability Considerations............................9
      4. Examples.......................................................9
      5. Security Considerations.......................................10
      6. IANA Considerations...........................................11
      7. Change History (to be deleted prior to RFC publication).......11
      8. Normative References..........................................12
      9. Informative References........................................13
      10. Acknowledgments..............................................13
      11. Author's Addresses...........................................14
   
   1. Introduction
   
      SNMP and the Internet-Standard Management Framework were
      originally devised to manage IP devices via in-band means where
      management access is primarily via the same interface(s) used to
      send and receive IP traffic.  SNMP's wide adoption has resulted in
      its use to manage communication devices that do not support in-
      band IP access (e.g., Fibre Channel devices); a separate out-of-
      band IP interface is often used for management.  URIs provide a
      convenient way to locate that interface and specify the protocol
      to be used for management; one possible scenario is for an in-band
      query to return a URI that indicates how the device is managed.
      This document specifies a URI scheme to permit SNMP (including a
      specific SNMP context) to be designated as the management protocol
      by such a URI.  This scheme also allows a URI to refer to specific
      object instances within an SNMP MIB.
   
      For a detailed overview of the documents that describe the current
      Internet-Standard Management Framework, please refer to section 7
      of [RFC 3410].
   
   
   
   
   
   
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   2. Syntax of an SNMP URI
   
      An SNMP URI has the following ABNF [RFC 2234] syntax:
   
         snmp_URI    = "snmp:" "//" [ user "@" ] host [ ":" port ]
                        [ "/" context [ ";" "engine=" engine ]
                          [ "/" ( oid | oid-group ) [ "+" | ".*" ]]]
         user        = < SNMP user name as specified by [RFC 3414] >
         host        = < as specified by [rfc2396bis] >
         port        = < as specified by [rfc2396bis] >
         engine      = hex [ (hex)* ] ; SNMP contextEngineID as
                         ; specified by [RFC 3411]
         hex         = < Hex digit, as specified by [rfc2396bis] >
         context     = < SNMP context name as specified by [RFC 3411] >
         oid-group   = "(" oid [ ( "," oid )* ] ")"
         oid         = < as specified by [RFC 3061] >
   
      The [ user "@" ] host [ ":" port ] portion of the above syntax
      matches the URI authority syntax specified in section 3 of
      [rfc2396bis] with the additional restriction that (when present)
      the user component (userinfo in [rfc2396bis]) MUST be an SNMP user
      name.  If the user is empty or not given, the entity making use of
      an SNMP URI is expected to know what SNMP user name to use if one
      is required.  If the port is empty or not given, port 161 is
      assumed.  If the context is empty or not given, the zero-length
      string ("") is assumed, as it is the default SNMP context.
   
      An SNMP contextEngineID is a variable-format binary element that
      is usually discovered by an SNMP Manager.  If the engine is empty
      or not given, the engine is to be discovered by interrogating the
      SNMP Agent at the specified host and port; see Section 3.1.
   
      An SNMP URI that designates the default SNMP context ("") MAY end
      with the "/" character that introduces the context component.  An
      SNMP URI MUST NOT end with the "/" character that introduces the
      oid or oid-group component, as the empty string is not a valid oid
      for SNMP.
   
      The encoding rules specified in [rfc2396bis] apply to SNMP URIs,
      including the use of percent encoding ("%" character followed by
      two hex digits) to represent characters other than unreserved
      characters.  SNMP allows any UTF-8 character to be used in a user
      name or context name; all multi-byte UTF-8 characters in an SNMP
      URI MUST be percent encoded as specified in Section 2.4 of
      [rfc2396bis].
   
      SNMP URIs will generally be short enough to avoid implementation
      string length limits (e.g., that may occur at 255 characters).
   
   
   
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      Use of IP addresses in SNMP URIs is acceptable in situations where
      dependence on availability of DNS service is undesirable or must
      be avoided; otherwise IP addresses should not be used (see [RFC
      1900] for further explanation).
   
   2.1 Relative URI Considerations
   
      Use of the SNMP default context (zero-length string) within an
      SNMP URI can result in a second instance of "//" in the URI, e.g.:
   
          snmp://<host>//<oid>
   
      This is allowed by [rfc2396bis]; if a URI parser does not handle
      the second "//" correctly, the parser is broken and needs to be
      fixed.  This example is important because use of the SNMP default
      context in SNMP URIs is expected to be common.
   
      On the other hand, the second occurrence of "//" in an absolute
      SNMP URI affects usage of relative URIs because a "//" at the
      start of a relative URI always introduces an authority component.
      Specifically, a relative SNMP URI of the form //<oid2> is not
      usable because the "//" causes <oid2> to be parsed as an
      authority, resulting in a syntax error.  To avoid this problem,
      relative SNMP URIs that start with "//" but do not contain an
      authority component MUST NOT be used.  The intended functionality
      of such relative URIs can be achieved by prefixing a "." or "..",
      depending on the base URI (e.g., ..//<oid2>).
   
   3. Semantics and Operations
   
      An SNMP URI that does not include any oids is called an SNMP
      service URI because it designates a communication endpoint for
      access to SNMP management service.  An SNMP URI that includes one
      or more oids is called an SNMP object URI because it designates
      one or more object instances in an SNMP MIB.
   
   3.1 SNMP Service URIs
   
      An SNMP service URI does not designate a data object, but rather
      an SNMP context to be accessed by a service; the telnet URI scheme
      [RFC 1738] is another example of URIs that designate service
      access.  The expected means of using an SNMP service URI is to
      employ an SNMP Manager to access the SNMP context designated by
      the URI via the SNMP Agent at the host and port designated by the
      URI; if the context is empty or not given in the URI, "" (the
      zero-length string) is assumed as it is the default SNMP context.
   
      If an engine is given in an SNMP service URI, the context is to be
      accessed via that SNMP engine.  If the engine is empty or not
   
   
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      given in the URI, the engine is to be discovered; the engine to be
      used is the one that supports the context designated by the URI.
      The engine component of the URI SHOULD be present if more than one
      engine at the designated host and port supports the designated
      context.
   
      Many common uses of SNMP URIs are expected to omit (i.e., default)
      both the engine and the context because they do not involve
      accessing SNMP proxy agents, the most common reason for multiple
      SNMP engines to exist at a single host and port.  Specifically,
      when an SNMP Agent is local to the network interface that it
      manages, the agent will usually have only one engine, in which
      case it is safe to omit the engine component of an SNMP URI.  In
      addition, many SNMP Agents that are local to a network interface
      support only the default SNMP context (zero-length string).
   
   3.2 SNMP Object URIs
   
      An SNMP object URI contains one or more oids.  The URI is used by
      first separating the oid or oid group (including its preceding
      slash plus any parentheses and/or suffix), and then processing the
      resulting SNMP service URI as specified in Section 3.1 (above) to
      determine the SNMP context to be accessed.  The engine component
      of the URI SHOULD be present if more than one engine at the
      designated host and port supports the designated context.  The oid
      or oid group is then used to generate SNMP operations directed to
      that SNMP context.
   
      The semantics of an SNMP object URI depend on whether the oid or
      oid group has a suffix and what that suffix is.  There are three
      possible suffix formats; in each case, the MIB object instances
      are designated within the SNMP context specified by the service
      URI portion of the SNMP object URI.  The semantics of an SNMP
      object URI that contains a single oid are:
   
      (1) An oid without a suffix designates the MIB object
         instance named by the oid.
      (2) An oid with a "+" suffix designates the lexically next
         MIB object instance following the oid.
      (3) An oid with a ".*" suffix designates the set of MIB
         object instances for which the oid is a strict lexical prefix;
         this does not include the MIB object instance named by the oid.
   
      An oid group in an SNMP URI consists of a set of oids in
      parentheses.  For cases (1) and (2), the oid group semantics are
      the extension of the single oid semantics to each oid in the group
      (e.g., in case (2) the URI designates the set of MIB object
      instances consisting of the lexically next object instance for
      each oid in the group).  For case (3), the oid group semantics are
   
   
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      an iterated version of case (2) where the iteration ceases when
      any element of the group fails to yield a valid MIB object
      instance.
   
      When there is a choice among suffix formats to designate the same
      MIB object instance or instances, the above list is in order of
      preference (no suffix is most preferable) as it runs from most
      precise to least precise.  This is because an oid without a suffix
      precisely designates an object instance, whereas a "+" suffix
      designates the next object instance, which may change, and the
      ".*" suffix could designate multiple object instances.  Multiple
      syntactically distinct SNMP URIs SHOULD NOT be used to designate
      the same MIB object instance or set of instances as this may cause
      unexpected results in URI-based systems that use string comparison
      to test URIs for equality.
   
      Data access based on an SNMP URI returns an SNMP variable binding
      for each MIB object instance designated by the URI.  An SNMP
      variable binding binds a variable name (oid) to a value or SNMP
      exception (see [RFC 3416]).  The SNMP operation or operations
      generated to access data designated by an SNMP object URI depend
      on the oid or oid group suffix or absence thereof:
   
      (1) For an oid or oid group without a suffix, an SNMP Get
         operation is generated using each oid as a variable binding
         name.  If an SNMP error occurs, that error is the result
         of URI data access.  If any returned variable binding
         contains a "noSuchObject" exception or a "noSuchInstance"
         exception, all bindings are ignored and URI data access is
         successful but returns no data.  Otherwise the returned
         variable bindings are the result of URI data access.
   
      (2) For an oid or oid group with a "+" suffix, an SNMP GetNext
         operation is generated using each oid as a variable binding
         name.  If an SNMP error occurs, that error is the result
         of URI data access.  If any returned variable binding contains
         an "endOfMibView" exception, all bindings are ignored and URI
         data access is successful but returns no data.  Otherwise the
         returned variable bindings are the result of URI data access.
   
      (3) For an oid or oid group with a ".*" suffix, an SNMP GetNext
         operation is initially generated using each oid as a variable
         binding name.  If the result is an SNMP error, that error is
         the result of URI data access.  If any returned variable
         binding contains an oid for which the corresponding URI oid is
         not a lexical prefix or contains an "endOfMibView" exception,
         all bindings are ignored and the URI data access is successful
         but returns no data.
   
   
   
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         Otherwise the results of the GetNext operation are saved, and
         another SNMP GetNext operation is generated using the newly
         returned oids as variable binding names; this is iterated until
         a GetNext operation returns one of the following:
   
           a) an SNMP error
           b) a variable binding containing an oid for which the
              corresponding URI oid is not a lexical prefix
           c) a variable binding containing an "endOfMibView" exception
   
         The iteration ceases at this point, and the results of this
         final SNMP GetNext operation are ignored.  The result of URI
         data access consists of the groups of variable bindings from
         the preceding successful SNMP GetNext operations.  SNMP
         GetBulk operations MAY be used to optimize this iterated
         access.
   
      Any applicable SNMP operation, including GetBulk, MAY be used to
      access data for all or part of multiple SNMP URIs (e.g., via use
      of multiple variable bindings in a single operation).  The use of
      relative object URIs that do not change context (i.e., ./oid)
      should be viewed as a hint that optimization is possible.  This
      can be useful when independent iteration is desired on multiple
      oids in the same context, as use of two URIs (e.g., base and
      relative) with the ".*" suffix will cause both iterations to run
      to their respective ends.  In contrast, when ".*" is applied to an
      oid group the iteration stops when any oid in the group can no
      longer be iterated.
   
      SNMP operations can bind oids to SNMP exceptions ("noSuchObject",
      "noSuchInstance", and "endOfMibView") that indicate no data is
      available for the requested binding.  The design of SNMP URIs
      shields URI users from such exceptions for simplicity.  The
      results of any successful SNMP operation that returns such an
      exception are ignored; that SNMP operation is considered to have
      succeeded and returned no data.  This is analogous to successful
      HTTP access to an empty web page (e.g., an HTTP 204 No Content
      status code as opposed to a 404 Not Found status code for a page
      that does not exist [RFC 2616]).
   
      An SNMP URI can also be used to specify a MIB object instance or
      instances to be written; this causes generation of an SNMP Set
      operation instead of a Get.  The "+" and ".*" suffixes MUST NOT be
      used in this case; any attempt to do so is an error and MUST NOT
      generate any SNMP Set operations.  The values to be written to the
      MIB object instances are not specified within the SNMP URI.
   
   
   
   
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   3.3 OID Groups in SNMP URIs
   
      Parenthesized oid groups in SNMP URIs are intended to support MIB
      object instances for which access via a single SNMP operation is
      required to ensure consistent results.  Therefore, the oids within
      an oid group in an SNMP URI SHOULD be accessed by a single SNMP
      operation with a variable binding corresponding to each oid in the
      group.  A specific example involves the InetAddress and
      InetAddressType textual conventions defined in [RFC 3291]; the
      format of an InetAddress instance is specified by an associated
      InetAddressType instance.  If two such associated instances are
      accessed via separate SNMP operations, the resulting values could
      be inconsistent (e.g., due to an intervening Set) causing the
      InetAddress value to be incorrectly interpreted.  This single
      operation requirement ("SHOULD") also applies to each oid group
      resulting from iterated access for an SNMP URI that contains ".*".
   
      The data designated by a ".*" format SNMP URI is based on
      iterating until at least one iterated oid fails to return data
      designated by the URI (original oid is not a lexical prefix of the
      returned oid, or an SNMP exception is returned).  This behavior
      differs from the corresponding behavior of the SNMP GetBulk
      operation which is only allowed to cease iterating early when no
      iterated oid returns useful data.  When any of a GetBulk's
      iterated oids stop returning useful data, bindings to
      "endOfMibView" exceptions are returned for those oids until
      iteration reaches the point that no iterated oid returns useful
      data (or the GetBulk operation is complete).  This approach is not
      applicable when an iterated oid from a ".*" format SNMP URI
      reaches the end of its lexical scope because the end of the MIB
      has not been reached, so using "endOfMibView" would be incorrect
      and risk misinterpretation by SNMP code.  Rather than inventing a
      new SNMP exception solely for ".*" format SNMP URIs, SNMP
      exceptions are hidden from URI users for simplicity.
   
      Given this approach, if the iteration for a ".*" format SNMP URI
      were to continue after an iterated oid has hit the end of its
      lexical prefix match, the size of subsequent groups of variable
      bindings would be smaller than the number of oids in the URI.
      This is counter to a more important aspect of GetBulk, namely that
      iteration results in matched sets of variable bindings (e.g., if
      there are three oids to be iterated [repeated], a set of three
      variable bindings for each iteration is returned).  In order to
      avoid returning smaller oid sets, the definition of a ".*" URI
      ceases iteration when any oid hits the end of its lexical prefix
      match or returns an SNMP exception.  This ensures that the
      structure of the information designated by a URI matches the
      structure of the URI's oid group (e.g., if the URI's oid group
   
   
   
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      contains three oids, the designated information consists of groups
      with three MIB object instances in each group).
   
      Relative URIs using ".*" provide almost as compact a specification
      of the independent iteration behavior of GetBulk, and as indicated
      above, use of relative URIs within the same context should be
      regarded as a hint that optimizations such as the use of GetBulk
      are possible.
   
   3.4 Interoperability Considerations
   
      This document defines a transport-independent "snmp:" scheme that
      is intended to accommodate SNMP transports other than UDP.  UDP is
      the default transport for access to information specified by an
      SNMP URI for backwards compatibility with existing usage, but
      other transports MAY be used.  If more than one transport can be
      used (e.g., SNMP over TCP [RFC 3430] in addition to SNMP over UDP)
      the information or SNMP service access designated by an SNMP URI
      SHOULD NOT depend on which transport is used (for SNMP over TCP,
      this is implied by Section 2 of [RFC 3430]).
   
      An SNMP URI designates use of SNMPv3 as specified by [RFC 3416],
      [RFC 3417] and related documents, but older versions of SNMP MAY
      be used for access designated by an SNMP URI in accordance with
      [RFC 3584] where usage of such older versions is unavoidable.
      SNMP versions (e.g., v3) have been omitted from the SNMP URI
      scheme for forwards compatibility with any possible future
      successor to SNMPv3.
   
   4. Examples
   
         snmp://snmp.example.com
   
      This example designates the default SNMP context at the SNMP Agent
      at UDP port 161 of host snmp.example.com .
   
         snmp://tester5@snmp.example.com:8161
   
      This example designates the default SNMP context at the SNMP Agent
      at UDP port 8161 of host snmp.example.com and indicates that the
      SNMP user name "tester5" is to be used to access that Agent.  A
      possible reason for use of a non-standard port is testing of a new
      version of SNMP Agent code.
   
         snmp://snmp.example.com/bridge1
   
      This example designates the "bridge1" SNMP context at
      snmp.example.com.  Because the engine component of the URI is
   
   
   
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      omitted, there SHOULD be at most one SNMP context engine at
      snmp.example.com that supports the "bridge1" context.
   
         snmp://snmp.example.com/bridge1;engine=800002b804616263
   
      This example designates the "bridge1" context at snmp.example.com
      via the SNMP contextEngineID 800002b804616263 (string
      representation of a hexadecimal value).  This avoids ambiguity if
      any other context engine supports a "bridge1" context.  The above
      two examples are based on the figure in Section 3.3 of [RFC 3411].
   
         snmp://snmp.example.com//1.3.6.1.2.1.1.3.0
         snmp://snmp.example.com//1.3.6.1.2.1.1.3+
         snmp://snmp.example.com//1.3.6.1.2.1.1.3.*
   
      These three examples all designate the sysUpTime.0 object instance
      in the SNMPv2-MIB for the default SNMP context ("") at
      snmp.example.com as sysUpTime.0 is:
         a) designated directly by oid 1.3.6.1.2.1.1.3.0,
         b) the lexically next MIB object instance after the oid
            1.3.6.1.2.1.1.3, and
         c) the only MIB object instance whose oid has 1.3.6.1.2.1.1.3
            as a lexical prefix.
      These three examples are provided for illustrative purposes only,
      as multiple syntactically distinct URIs SHOULD NOT be used to
      designate the same MIB object instance in order to avoid
      unexpected results in URI-based systems that use string comparison
      to test URIs for equality.
   
         snmp://example.com/bridge1/1.3.6.1.2.1.2.2.1.8.*
   
      This example designates the ifOperStatus column of the IF-MIB in
      the bridge1 SNMP context at example.com.
   
         snmp://example.com//(1.3.6.1.2.1.2.2.1.7,1.3.6.1.2.1.2.2.1.8).*
   
      This example designates all (ifAdminStatus, ifOperStatus) pairs in
      the IF-MIB in the default SNMP context at example.com.
   
   5. Security Considerations
   
      An intended use of this URI scheme is designation of the location
      of management access to communication devices.  Such location
      information may be considered sensitive in some environments,
      making it important to control even read access and possibly even
      to encrypt the information when sending it over the network.  All
      uses of this URI scheme should provide security mechanisms
      appropriate to the environments in which such uses are likely to
      be deployed.
   
   
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      There are management objects defined in SNMP MIBs whose MAX-ACCESS
      is read-write and/or read-create.  Such objects may be considered
      sensitive or vulnerable in some network environments.  The support
      for SNMP SET operations in a non-secure environment without proper
      protection can have a negative effect on network operations.  The
      individual MIB module specifications, and especially their
      security considerations, should be consulted for further
      information.
   
      Some readable objects in some MIB modules (i.e., objects with a
      MAX-ACCESS other than not-accessible) may be considered sensitive
      or vulnerable in some network environments.  It is thus important
      to control even GET access to these objects and possibly to even
      encrypt the values of these objects when sending them over the
      network via SNMP.  The individual MIB module specifications, and
      especially their security considerations, should be consulted for
      further information.  This consideration also applies to objects
      for which read operations have side effects.
   
      SNMP versions prior to SNMPv3 did not include adequate security.
      Even if the network itself is secure (for example via use of
      IPsec), there is no control over who on the secure network is
      allowed to access and GET/SET (read/change/create/delete) the
      objects in MIB modules. It is RECOMMENDED that implementers
      consider the security features as provided by the SNMPv3 framework
      (see [RFC 3410], section 8 for an overview), including full
      support for SNMPv3 cryptographic mechanisms (for authentication
      and privacy).  This is of additional importance for MIB elements
      considered sensitive or vulnerable because GETs have side effects.
   
      Further, deployment of SNMP versions prior to SNMPv3 is NOT
      RECOMMENDED.  Instead, it is RECOMMENDED to deploy SNMPv3 and to
      enable cryptographic security.  It is then a customer/operator
      responsibility to ensure that the SNMP entity giving access to a
      MIB module instance is properly configured to give access to the
      objects only to those principals (users) that have legitimate
      rights to indeed GET or SET (change/create/delete) them.
   
   6. IANA Considerations
   
      The IANA is asked to register the URL registration template found
      in Appendix A in accordance with [RFC 2717].
   
   7. Change History (to be deleted prior to RFC publication)
   
      -00: Initial version - user, host and port only.
      -01: Initial attempt to add engine, context, and oid, plus
         support for alternate (non-UDP) transports.
   
   
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      -02: Reworked engine, context, and oid syntax.  Made URI scheme
         transport-independent.  Added more examples.  Significant text
         editing and rearrangement.
      -03: Update to reference rfc2396bis draft instead of RFC 2396.
         Context and engine syntax changed to comply with rfc2396bis
         authority component restrictions.  Minor text editing.
      -04: Remove "0x" engine prefix.  Add discussion of relative
         URI impacts of embedded //.  Add oid groups to support
         MIB object instances that need to be accessed together.
         Always discard SNMP "no data" response exceptions.  More edits.
      -05: Spell out acronyms in title.  Correct wording to refer to
         SNMP exceptions.  More editing.
   
   8. Normative References
   
      [rfc2396bis] Uniform Resource Identifiers (URI): Generic Syntax.
                  T. Berners-Lee, R. Fielding, L. Masinter.
                  Internet-Draft draft-fielding-uri-rfc2396bis.
                  Work in Progress.  February 2004.
   
      [RFC 2119] Key words for use in RFCs to Indicate Requirement
                  Levels. S. Bradner. RFC 2119, BCP 14. March 1997.
   
      [RFC 2234] Augmented BNF for Syntax Specifications: ABNF.
                  D. Crocker, Ed., P. Overell. RFC 2234. November 1997.
   
      [RFC 3061] A URN Namespace of Object Identifiers.  M. Mealling.
                  February 2001.
   
      [RFC 3411] An Architecture for Describing Simple Network
                  Management Protocol (SNMP) Management Frameworks.
                   D. Harrington, R. Presuhn, B. Wijnen.  December 2002.
   
      [RFC 3414] User-based Security Model (USM) for version 3 of the
                  Simple Network Management Protocol (SNMPv3).
                  U. Blumenthal, B. Wijnen. RFC 3414. December 2002.
   
      [RFC 3416] Version 2 of the Protocol Operations for the Simple
                  Network Management Protocol (SNMP). R. Presuhn, Ed.
                  RFC 3416. December 2002.
   
      [RFC 3417] Transport Mappings for the Simple Network Management
                  Protocol (SNMP). R. Presuhn, Ed. RFC 3417.
                  December 2002.
   
      [RFC 3584] Coexistence between Version 1, Version 2, and Version 3
                  of the Internet-standard Network Management Framework.
                  R. Frye, D. Levi, S. Routhier, B. Wijnen. RFC 3584.
                  August 2003.
   
   
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                            URI Scheme for SNMP                 May 2004
   
   
   9. Informative References
   
      [RFC 1738] Uniform Resource Locators (URL). T. Berners-Lee,
                  L. Masinter, M. McCahill. RFC 1738. December 1994.
   
      [RFC 1900] Renumbering Needs Work. B. Carpenter, Y. Rekhter.
                  RFC 1900. February 1996.
   
      [RFC 2026] The Internet Standards Process -- Revision 3.
                  S. Bradner. RFC 2026, BCP 9. October 1996.
   
      [RFC 2616] Hypertext Transfer Protocol -- HTTP/1.1. R. Fielding,
                  J. Gettys, J. Mogul, H. Frystyk, L. Masinter,
                  P. Leach, T. Berners-Lee. RFC 2616. June 1999.
   
      [RFC 2717] Registration Procedures for URL Scheme Names. R. Petke,
                  I. King. RFC 2717. November 1999.
   
      [RFC 3291] Textual Conventions for Internet Network Addresses.
                  M. Daniele, B. Haberman, S. Routhier,
                  J. Schoenwaelder.  RFC 3291.  May 2002.
   
      [RFC 3410] Introduction and Applicability Statements for Internet-
                  Standard Management Framework. J. Case, R. Mundy,
                  D. Partain, B. Stewart. RFC 3410. December 2002.
   
      [RFC 3430] Simple Network Management Protocol Over Transmission
                  Control Protocol Transport Mapping. J. Schoenwaelder.
                  December 2002.
   
      [RFC 3617] Uniform Resource Identifier (URI) Scheme and
                  Applicability Statement for the Trivial File Transfer
                  Protocol (TFTP). E. Lear. October 2003.
   
   10. Acknowledgments
   
      Portions of this draft were adapted from Eliot Lear's TFTP URI
      scheme specification [RFC 3617].  The security considerations text
      was adapted from the widely used security considerations
      "boilerplate" for MIB modules.  Comments from Ted Hardie, Michael
      Mealing, Larry Masinter, and the uri@w3c.org mailing list on
      earlier versions of this draft have resulted in significant
      improvements and are gratefully acknowledged.
   
   
   
   
   
   
   
   
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                            URI Scheme for SNMP                 May 2004
   
   
   
   11. Author's Addresses
   
      David L. Black
      EMC Corporation
      176 South Street
      Hopkinton, MA 01748
      Phone: +1 (508) 293-7953
      Email: black_david@emc.com
   
      Keith McCloghrie
      Cisco Systems, Inc.
      170 West Tasman Drive
      San Jose, CA USA 95134
      Phone: +1 (408) 526-5260
      Email: kzm@cisco.com
   
      Juergen Schoenwaelder
      International University Bremen
      P.O. Box 750 561
      28725 Bremen
      Germany
      Phone: +49 421 200 3587
      Email: j.schoenwaelder@iu-bremen.de
   
   Appendix A. Registration Template
   
      URL scheme name: snmp
      URL scheme syntax: Section 2
      Character encoding considerations: Section 2
      Intended usage: Section 1
      Applications and/or protocols which use this scheme: SNMP, all
         versions, see [RFC 3410] and [RFC 3584].  Also SNMP over TCP,
         see [RFC 3430].
      Interoperability considerations: Section 3.4
      Security considerations: Section 5
      Relevant publications: See [RFC 3410] for list.  Also [RFC 3430]
         and [RFC 3584].
      Contact: David L. Black, Section 11
      Author/Change Controller: IESG
   
   
   
   
   
   
   
   
   
   
   
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