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RFC 2074 - Remote Network Monitoring MIB Protocol Identifiers


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Network Working Group                                       A. Bierman
Request for Comments: 2074                               Cisco Systems
Category: Standards Track                                     R. Iddon
                                                    AXON Networks,Inc.
                                                          January 1997

           Remote Network Monitoring MIB Protocol Identifiers

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Table of Contents

1 Introduction ....................................................    3
2 The SNMP Network Management Framework ...........................    3
2.1 Object Definitions ............................................    3
3 Overview ........................................................    3
3.1 Terms .........................................................    4
3.2 Relationship to the Remote Network Monitoring MIB .............    6
3.3 Relationship to the Other MIBs ................................    6
4 Protocol Identifier Encoding ....................................    7
4.1 ProtocolDirTable INDEX Format Examples ........................    9
4.2 Protocol Identifier Macro Format ..............................   10
4.2.1 Mapping of the Protocol Name ................................   12
4.2.2 Mapping of the VARIANT-OF Clause ............................   13
4.2.3 Mapping of the PARAMETERS Clause ............................   13
4.2.3.1 Mapping of the 'countsFragments(0)' BIT ...................   14
4.2.3.2 Mapping of the 'tracksSessions(1)' BIT ....................   15
4.2.4 Mapping of the ATTRIBUTES Clause ............................   15
4.2.5 Mapping of the DESCRIPTION Clause ...........................   15
4.2.6 Mapping of the CHILDREN Clause ..............................   16
4.2.7 Mapping of the ADDRESS-FORMAT Clause ........................   16
4.2.8 Mapping of the DECODING Clause ..............................   16
4.2.9 Mapping of the REFERENCE Clause .............................   17
4.2.10 Evaluating a Protocol-Identifier INDEX .....................   17
5 Protocol Identifier Macros ......................................   18
5.1 Base Identifier Encoding ......................................   18
5.1.1 Protocol Identifier Functions ...............................   19
5.1.1.1 Function 0: No-op .........................................   19
5.1.1.2 Function 1: Protocol Wildcard Function ....................   19
5.2 Base Layer Protocol Identifiers ...............................   20
5.2.1 Ether2 Encapsulation ........................................   21

5.2.2 LLC Encapsulation ...........................................   22
5.2.3 SNAP over LLC (OUI=000) Encapsulation .......................   23
5.2.4 SNAP over LLC (OUI != 000) Encapsulation ....................   24
5.2.5 IANA Assigned Protocols .....................................   25
5.2.5.1 IANA Assigned Protocol Identifiers ........................   27
5.3 L3: Children of Base Protocol Identifiers .....................   27
5.3.1 IP ..........................................................   28
5.3.2 IPX .........................................................   29
5.3.3 ARP .........................................................   30
5.3.4 IDP .........................................................   30
5.3.5 AppleTalk ARP ...............................................   31
5.3.6 AppleTalk ...................................................   31
5.4 L4: Children of L3 Protocols ..................................   32
5.4.1 ICMP ........................................................   32
5.4.2 TCP .........................................................   32
5.4.3 UDP .........................................................   33
5.5 L5: Application Layer Protocols ...............................   33
5.5.1 FTP .........................................................   33
5.5.1.1 FTP-DATA ..................................................   33
5.5.1.2 FTP Control ...............................................   34
5.5.2 Telnet ......................................................   34
5.5.3 SMTP ........................................................   34
5.5.4 DNS .........................................................   35
5.5.5 BOOTP .......................................................   35
5.5.5.1 Bootstrap Server Protocol .................................   35
5.5.5.2 Bootstrap Client Protocol .................................   35
5.5.6 TFTP ........................................................   36
5.5.7 HTTP ........................................................   36
5.5.8 POP3 ........................................................   36
5.5.9 SUNRPC ......................................................   37
5.5.10 NFS ........................................................   38
5.5.11 SNMP .......................................................   38
5.5.11.1 SNMP Request/Response ....................................   38
5.5.11.2 SNMP Trap ................................................   39
6 Acknowledgements ................................................   39
7 References ......................................................   40
8 Security Considerations .........................................   43
9 Authors' Addresses ..............................................   43

1.  Introduction

   This memo defines an experimental portion of the Management
   Information Base (MIB) for use with network management protocols in
   the Internet community.  In particular, it describes the algorithms
   required to identify different protocol encapsulations managed with
   the Remote Network Monitoring MIB Version 2 [RMON2]. Although related
   to the original Remote Network Monitoring MIB [RFC1757], this
   document refers only to objects found in the RMON-2 MIB.

2.  The SNMP Network Management Framework

   The SNMP Network Management Framework presently consists of three
   major components.  They are:

o    the SMI, described in RFC 1902 [RFC1902], - the mechanisms used for
     describing and naming objects for the purpose of management.

o    the MIB-II, STD 17, RFC 1213 [RFC1213], - the core set of managed
     objects for the Internet suite of protocols.

o    the protocol, STD 15, RFC 1157 [RFC1157] and/or RFC 1905 [RFC1905],
     - the protocol for accessing managed information.

   Textual conventions are defined in RFC 1903 [RFC1903], and
   conformance statements are defined in RFC 1904 [RFC1904].

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

2.1.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1)
   defined in the SMI.  In particular, each object type is named by an
   OBJECT IDENTIFIER, an administratively assigned name.  The object
   type together with an object instance serves to uniquely identify a
   specific instantiation of the object.  For human convenience, we
   often use a textual string, termed the descriptor, to refer to the
   object type.

3.  Overview

   The RMON-2 MIB [RMON2] uses hierarchically formatted OCTET STRINGs to
   globally identify individual protocol encapsulations in the
   protocolDirTable.

   This guide contains algorithms and examples of protocol identifier
   encapsulations for use as INDEX values in the protocolDirTable.

   This document is not intended to be an authoritative reference on the
   protocols described herein. Refer to the Official Internet Standards
   document [RFC1800], the Assigned Numbers document [RFC1700], or other
   appropriate RFCs, IEEE documents, etc. for complete and authoritative
   protocol information.

3.1.  Terms

   Several terms are used throughout this document, as well as in the
   RMON-2 MIB [RMON2], that should be introduced:

layer-identifier:
     An octet string fragment representing a particular protocol
     encapsulation layer. A string fragment identifying a particular
     protocol encapsulation layer. This string is exactly four octets,
     (except for the 'vsnap' base-layer identifier, which is exactly
     eight octets) encoded in network byte order. A particular protocol
     encapsulation can be identified by starting with a base layer
     encapsulation (see the 'Base Protocol Identifiers' section for more
     detail), and following the encoding rules specified in the CHILDREN
     clause and assignment section for that layer. Then repeat for each
     identified layer in the encapsulation. (See section 4.2.10
     'Evaluating a Protocol-Identifier INDEX' for more detail.)

protocol:
     A particular protocol layer, as specified by encoding rules in this
     document. Usually refers to a single layer in a given
     encapsulation. Note that this term is sometimes used in the RMON-2
     MIB [RMON2] to name a fully-specified protocol-identifier string.
     In such a case, the protocol-identifier string is named for its
     upper-most layer. A named protocol may also refer to any
     encapsulation of that protocol.

protocol-identifier string:
     An octet string representing a particular protocol encapsulation,
     as specified by encoding rules in this document. This string is
     identified in the RMON-2 MIB [RMON2] as the protocolDirID object. A
     protocol-identifier string is composed of one or more layer-
     identifiers.

protocol-identifier macro:
     A group of formatted text describing a particular protocol layer,
     as used within the RMON-2 MIB [RMON2]. The macro serves several
     purposes:

     - Name the protocol for use within the RMON-2 MIB [RMON2].
     - Describe how the protocol is encoded into an octet string.
     - Describe how child protocols are identified (if applicable),
       and encoded into an octet string.
     - Describe which protocolDirParameters are allowed for the protocol.
     - Describe how the associated protocolDirType object is encoded
       for the protocol.
     - Provide reference(s) to authoritative documentation for the
       protocol.

protocol-variant-identifier macro:
     A group of formatted text describing a particular protocol layer,
     as used within the RMON-2 MIB [RMON2]. This protocol is a variant
     of a well known encapsulation that may be present in the
     protocolDirTable. This macro is used to document the IANA
     assigned protocols, which are needed to identify protocols which
     cannot be practically identified by examination of 'appropriate
     network traffic' (e.g. the packets which carry them). All other
     protocols (which can be identified by examination of appropriate
     network traffic) should be documented using the protocol-identifier
     macro. A protocol-variant-identifier is documented using the
     protocol-variant version of the protocol-identifier macro.

protocol-parameter:
     A single octet, corresponding to a specific layer-identifier in the
     protocol-identifier. This octet is a bit-mask indicating special
     functions or capabilities that this agent is providing for the
     corresponding protocol.

protocol-parameters string:
     An octet string, which contains one protocol-parameter for each
     layer-identifier in the protocol-identifier.  See the section
     'Mapping of the PARAMETERS Clause' for more detail.  This string is
     identified in the RMON-2 MIB [RMON2] as the protocolDirParameters
     object.

protocolDirTable INDEX:
     A protocol-identifier and protocol-parameters octet string pair
     that have been converted to an INDEX value, according to the
     encoding rules in in section 7.7 of RFC 1902 [RFC1902].

pseudo-protocol:
     A convention or algorithm used only within this document for the
     purpose of encoding protocol-identifier strings.

3.2.  Relationship to the Remote Network Monitoring MIB

   This document is intended to identify possible string values for the
   OCTET STRING objects protocolDirID and protocolDirParameters.  Tables
   in the new Protocol Distribution, Host, and Matrix groups use a local
   INTEGER INDEX, in order to remain unaffected by changes in this
   document. Only the protocolDirTable uses the strings (protocolDirID
   and protocolDirParameters) described in this document.

   This document is not intended to limit the protocols that may be
   identified for counting in the RMON-2 MIB. Many protocol
   encapsulations, not explicitly identified in this document, may be
   present in an actual implementation of the protocolDirTable. Also,
   implementations of the protocolDirTable may not include all the
   protocols identified in the example section below.

   This document is intentionally separated from the MIB objects to
   allow frequent updates to this document without any republication of
   MIB objects.  Protocol Identifier macros submitted from the RMON
   working group and community at large (to the RMONMIB WG mailing list
   at 'rmonmib@cisco.com') will be collected and added to this document.

   Macros submissions will be collected in the IANA's MIB files under
   the directory "ftp://ftp.isi.edu/mib/rmonmib/rmon2_pi_macros/" and in
   the RMONMIB working group mailing list message archive file
   "ftp://ftp.cisco.com/ftp/rmonmib/rmonmib".

   This document does not discuss auto-discovery and auto-population of
   the protocolDirTable. This functionality is not explicitly defined by
   the RMON standard. An agent should populate the directory with
   'interesting' protocols--depending on the intended applications.

3.3.  Relationship to the Other MIBs

   The RMON Protocol Identifiers document is intended for use with the
   protocolDirTable within the RMON MIB. It is not relevant to any other
   MIB, or intended for use with any other MIB.

4.  Protocol Identifier Encoding

   The protocolDirTable is indexed by two OCTET STRINGs, protocolDirID
   and protocolDirParameters. To encode the table index, each variable-
   length string is converted to an OBJECT IDENTIFIER fragment,
   according to the encoding rules in section 7.7 of RFC 1902 [RFC1902].
   Then the index fragments are simply concatenated. (Refer to figures
   1a - 1d below for more detail.)

   The first OCTET STRING (protocolDirID) is composed of one or more 4-
   octet "layer-identifiers". The entire string uniquely identifies a
   particular protocol encapsulation tree. The second OCTET STRING,
   (protocolDirParameters) which contains a corresponding number of 1-
   octet protocol-specific parameters, one for each 4-octet layer-
   identifier in the first string.

   A protocol layer is normally identified by a single 32-bit value.
   Each layer-identifier is encoded in the ProtocolDirID OCTET STRING
   INDEX as four sub-components [ a.b.c.d ], where 'a' - 'd' represent
   each byte of the 32-bit value in network byte order.  If a particular
   protocol layer cannot be encoded into 32 bits, (except for the
   'vsnap' base layer) then it must be defined as a 'ianaAssigned'
   protocol (see below for details on IANA assigned protocols).

   The following figures show the differences between the OBJECT
   IDENTIFIER and OCTET STRING encoding of the protocol identifier
   string.

                   Fig. 1a
         protocolDirTable INDEX Format
         -----------------------------

     +---+--------------------------+---+---------------+
     | c !                          | c !  protocolDir  |
     | n !  protocolDirID           | n !  Parameters   |
     | t !                          | t !               |
     +---+--------------------------+---+---------------+

                   Fig. 1b
         protocolDirTable OCTET STRING Format
         ------------------------------------

      protocolDirID
     +----------------------------------------+
     |                                        |
     |              4 * N octets              |
     |                                        |
     +----------------------------------------+

     protocolDirParameters
     +----------+
     |          |
     | N octets |
     |          |
     +----------+

                    Fig. 1c
        protocolDirTable INDEX Format Example
        -------------------------------------

     protocolDirID                   protocolDirParameters
     +---+--------+--------+--------+--------+---+---+---+---+---+
     | c |  proto |  proto |  proto |  proto | c |par|par|par|par|
     | n |  base  |    L3  |   L4   |   L5   | n |ba-| L3| L4| L5|
     | t |(+flags)|        |        |        | t |se |   |   |   |
     +---+--------+--------+--------+--------+---+---+---+---+---+ subOID
     | 1 | 4 or 8 |    4   |    4   |    4   | 1 |1/2| 1 | 1 | 1 | count

     where N is the number of protocol-layer-identifiers required
     for the entire encapsulation of the named protocol. Note that
     the 'vsnap' base layer identifier is encoded into 8 sub-identifiers,
     All other protocol layers are either encoded into 4 sub-identifiers
     or encoded as a 'ianaAssigned' protocol.

                    Fig. 1d
       protocolDirTable OCTET STRING Format Example
       --------------------------------------------

     protocolDirID
     +--------+--------+--------+--------+
     |  proto |  proto |  proto |  proto |
     |   base |    L3  |   L4   |   L5   |
     |        |        |        |        |
     +--------+--------+--------+--------+ octet
     | 4 or 8 |    4   |    4   |    4   | count

     protocolDirParameters
     +---+---+---+---+
     |par|par|par|par|
     |ba-| L3| L4| L5|
     |se |   |   |   |
     +---+---+---+---+ octet
     |1/2| 1 | 1 | 1 | count

     where N is the number of protocol-layer-identifiers required
     for the entire encapsulation of the named protocol. Note that
     the 'vsnap' base layer identifier is encoded into 8
     protocolDirID sub-identifiers and 2 protocolDirParameters
     sub-identifiers.

   Although this example indicates four encapsulated protocols, in
   practice, any non-zero number of layer-identifiers may be present,
   theoretically limited only by OBJECT IDENTIFIER length restrictions,
   as specified in section 3.5 of RFC 1902 [RFC1902].

   Note that these two strings would not be concatenated together if
   ever returned in a GetResponse PDU, since they are different MIB
   objects.  However, protocolDirID and protocolDirParameters are not
   currently readable MIB objects.

4.1.  ProtocolDirTable INDEX Format Examples

    -- HTTP; fragments counted from IP and above
    ether2.ip.tcp.www-http =
       16.0.0.0.1.0.0.8.0.0.0.0.6.0.0.0.80.4.0.1.0.0

    -- SNMP over UDP/IP over SNAP
    snap.ip.udp.snmp =
       16.0.0.0.3.0.0.8.0.0.0.0.17.0.0.0.161.4.0.0.0.0

    -- SNMP over IPX over SNAP
    snap.ipx.snmp =
       12.0.0.0.3.0.0.129.55.0.0.144.15.3.0.0.0

    -- SNMP over IPX over raw8023
    -- ianaAssigned(ipxOverRaw8023(1)).snmp =
       12.0.0.0.5.0.0.0.1.0.0.155.15.3.0.0.0

    -- IPX over LLC
    llc.ipx =
       8.0.0.0.2.0.224.224.3.2.0.0

    -- SNMP over UDP/IP over any link layer
    -- wildcard-ether2.ip.udp.snmp
       16.1.0.0.1.0.0.8.0.0.0.0.17.0.0.0.161.4.0.0.0.0

    -- IP over any link layer; base encoding is IP over ether2
    -- wildcard-ether2.ip
       8.1.0.0.1.0.0.8.0.2.0.0

   -- AppleTalk Phase 2 over ether2
   -- ether2.atalk
      8.0.0.0.1.0.0.128.155.2.0.0

   -- AppleTalk Phase 2 over vsnap
   -- vsnap(apple).atalk
      12.0.0.0.4.0.8.0.7.0.0.128.155.3.0.0.0

4.2.  Protocol Identifier Macro Format

   The following example is meant to introduce the protocol-identifier
   macro. (The syntax is not quite ASN.1.) This macro is used to
   represent both protocols and protocol-variants.

   If the 'VariantOfPart' component of the macro is present, then the
   macro represents a protocol-variant instead of a protocol.  A
   protocol- variant-identifier is used only for IANA assigned
   protocols, enumerated under the 'ianaAssigned' base-layer.

     RMON-PROTOCOL-IDENTIFIER MACRO ::=
     BEGIN
             PIMacroName "PROTOCOL-IDENTIFIER"
                     VariantOfPart
                     "PARAMETERS"   ParamPart
                     "ATTRIBUTES"   AttrPart
                     "DESCRIPTION"  Text
                     ChildDescrPart
                     AddrDescrPart
                     DecodeDescrPart
                     ReferPart
             "::=" "{" EncapsPart "}"

             PIMacroName ::=
                 identifier

             VariantOfPart ::=
                 "VARIANT-OF" identifier | empty

             ParamPart ::=
                 "{" ParamList "}"

             ParamList ::=
                 Params | empty

             Params ::=
                 Param | Params "," Param

             Param ::=
                 identifier "(" nonNegativeNumber ")"

             AttrPart ::=
                 "{" AttrList "}"

             AttrList ::=
                 Attrs | empty

             Attrs ::=
                 Attr | Attrs "," Attr

             Attr ::=
                 identifier "(" nonNegativeNumber ")"

             ChildDescrPart ::=
                 "CHILDREN" Text | empty

             AddrDescrPart ::=
                 "ADDRESS-FORMAT" Text | empty

             DecodeDescrPart ::=
                 "DECODING" Text | empty

             ReferPart ::=
                 "REFERENCE" Text | empty

             EncapsPart ::=
                 "{" Encaps "}"

             Encaps ::=
                 Encap | Encaps "," Encap

             Encap ::=
                 BaseEncap | NormalEncap | VsnapEncap | IanaEncap

             BaseEncap ::=
                 nonNegativeNumber

             NormalEncap ::=
                 identifier nonNegativeNumber

             VsnapEncap ::=
                 identifier "(" nonNegativeNumber ")" nonNegativeNumber

             IanaEncap ::=
                 "ianaAssigned" nonNegativeNumber
                 | "ianaAssigned" identifier
                 | "ianaAssigned" identifier "(" nonNegativeNumber ")"

             Text ::=
                 """" string """"
     END

4.2.1.  Mapping of the Protocol Name

   The 'PIMacroName' value should be a lower-case ASCII string, and
   contain the name or acronym identifying the protocol.  NMS
   applications may treat protocol names as case-insensitive strings,
   and agent implementations must make sure the protocolDirTable does
   not contain any instances of the protocolDirDescr object which differ
   only in the case of one of more letters (if the identifiers are
   intended to represent different protocols).

   It is possible that different encapsulations of the same protocol
   (which are represented by different entries in the protocolDirTable)
   will be assigned the same protocol name.

   A protocol name should match the "most well-known" name or acronym
   for the indicated protocol.  For example, the document indicated by
   the URL:

       ftp://ftp.isi.edu/in-notes/iana/assignments/protocol-numbers

   defines IP Protocol field values, so protocol-identifier macros for
   children of IP should be given names consistent with the protocol
   names found in this authoritative document.

4.2.2.  Mapping of the VARIANT-OF Clause

   This clause is present for IANA assigned protocols only.  It
   identifies the protocol-identifier macro that most closely represents
   this particular protocol, and is known as the "reference protocol".
   (A protocol-identifier macro must exist for the reference protocol.)
   When this clause is present in a protocol-identifier macro, the macro
   is called a 'protocol-variant-identifier'.

   Any clause (e.g. CHILDREN, ADDRESS-FORMAT) in the reference protocol-
   identifier macro should not be duplicated in the protocol-variant-
   identifier macro, if the 'variant' protocols' semantics are identical
   for a given clause.

   Since the PARAMETERS and ATTRIBUTES clauses must be present in a
   protocol-identifier, an empty 'ParamPart' and 'AttrPart' (i.e.
   "PARAMETERS {}") must be present in a protocol-variant-identifier
   macro, and the 'ParamPart' and 'AttrPart' found in the reference
   protocol- identifier macro examined instead.

   Note that if a 'ianaAssigned' protocol is defined that is not a
   variant of any other documented protocol, then the protocol-
   identifier macro should be used instead of the protocol-variant-
   identifier version of the macro.

4.2.3.  Mapping of the PARAMETERS Clause

   The protocolDirParameters object provides an NMS the ability to turn
   on and off expensive probe resources. An agent may support a given
   parameter all the time, not at all, or subject to current resource
   load.

   The PARAMETERS clause is a list of bit definitions which can be
   directly encoded into the associated ProtocolDirParameters octet in
   network byte order. Zero or more bit definitions may be present. Only
   bits 0-7 are valid encoding values. This clause defines the entire
   BIT set allowed for a given protocol. A conforming agent may choose
   to implement a subset of zero or more of these PARAMETERS.

   By convention, the following common bit definitions are used by
   different protocols.  These bit positions must not be used for other
   parameters. They should be reserved if not used by a given protocol.
   Bits are encoded in network-byte order.

         Table 3.1  Reserved PARAMETERS Bits
         ------------------------------------

Bit Name              Description
---------------------------------------------------------------------
0   countsFragments   higher-layer protocols encapsulated within
                      this protocol will be counted correctly even
                      if this protocol fragments the upper layers
                      into multiple packets.
1   tracksSessions    correctly attributes all packets of a protocol
                      which starts sessions on well known ports or
                      sockets and then transfers them to dynamically
                      assigned ports or sockets thereafter (e.g. TFTP).

   The PARAMETERS clause must be present in all protocol-identifier
   macro declarations, but may be equal to zero (empty). Note that an
   NMS must determine if a given PARAMETER bit is supported by
   attempting to create the desired protocolDirEntry The associated
   ATTRIBUTE bits for 'countsFragments' and 'tracksSessions' do not
   exist.

4.2.3.1.  Mapping of the 'countsFragments(0)' BIT

   This bit indicates whether the probe is correctly attributing all
   fragmented packets of the specified protocol, even if individual
   frames carrying this protocol cannot be identified as such.  Note
   that the probe is not required to actually present any re-assembled
   datagrams (for address-analysis, filtering, or any other purpose) to
   the NMS.

   This bit may only be set in a protocolDirParameters octet which
   corresponds to a protocol that supports fragmentation and reassembly
   in some form. Note that TCP packets are not considered 'fragmented-
   streams' and so TCP is not eligible.

   This bit may be set in at most one protocolDirParameters octet within
   a protocolDirTable INDEX.

4.2.3.2.  Mapping of the 'tracksSessions(1)' BIT

   The 'tracksSessions(1)' bit indicates whether frames which are part
   of remapped-sessions (e.g. TFTP download sessions) are correctly
   counted by the probe. For such a protocol, the probe must usually
   analyze all packets received on the indicated interface, and maintain
   some state information, (e.g. the remapped UDP port number for TFTP).

   The semantics of the 'tracksSessions' parameter are independent of
   the other protocolDirParameters definitions, so this parameter may be
   combined with any other legal parameter configurations.

4.2.4.  Mapping of the ATTRIBUTES Clause

   The protocolDirType object provides an NMS with an indication of a
   probe's capabilities for decoding a given protocol, or the general
   attributes of the particular protocol.

   The ATTRIBUTES clause is a list of bit definitions which are encoded
   into the associated instance of ProtocolDirType. The BIT definitions
   are specified in the SYNTAX clause of the protocolDirType MIB object.

         Table 3.2  Reserved ATTRIBUTES Bits
         ------------------------------------

     Bit Name              Description
     ---------------------------------------------------------------------
     0  hasChildren        indicates that there may be children of
                           this protocol defined in the protocolDirTable
                           (by either the agent or the manager).
     1  addressRecognitionCapable
                           indicates that this protocol can be used
                           to generate host and matrix table entries.

   The ATTRIBUTES clause must be present in all protocol-identifier
   macro declarations, but may be empty.

4.2.5.  Mapping of the DESCRIPTION Clause

   The DESCRIPTION clause provides a textual description of the protocol
   identified by this macro.  Notice that it should not contain details
   about items covered by the CHILDREN, ADDRESS-FORMAT, DECODING and
   REFERENCE clauses.

   The DESCRIPTION clause must be present in all protocol-identifier
   macro declarations.

4.2.6.  Mapping of the CHILDREN Clause

   The CHILDREN clause provides a description of child protocols for
   protocols which support them. It has three sub-sections:

  -  Details on the field(s)/value(s) used to select the child protocol,
     and how that selection process is performed

  -  Details on how the value(s) are encoded in the protocol identifier
     octet string

  -  Details on how child protocols are named with respect to their
     parent protocol label(s)

   The CHILDREN clause must be present in all protocol-identifier macro
   declarations in which the 'hasChildren(0)' BIT is set in the
   ATTRIBUTES clause.

4.2.7.  Mapping of the ADDRESS-FORMAT Clause

   The ADDRESS-FORMAT clause provides a description of the OCTET-STRING
   format(s) used when encoding addresses.

   This clause must be present in all protocol-identifier macro
   declarations in which the 'addressRecognitionCapable(1)' BIT is set
   in the ATTRIBUTES clause.

4.2.8.  Mapping of the DECODING Clause

   The DECODING clause provides a description of the decoding procedure
   for the specified protocol. It contains useful decoding hints for the
   implementor, but should not over-replicate information in documents
   cited in the REFERENCE clause.  It might contain a complete
   description of any decoding information required.

   For 'extensible' protocols ('hasChildren(0)' BIT set) this includes
   offset and type information for the field(s) used for child selection
   as well as information on determining the start of the child
   protocol.

   For 'addressRecognitionCapable' protocols this includes offset and
   type information for the field(s) used to generate addresses.

   The DECODING clause is optional, and may be omitted if the REFERENCE
   clause contains pointers to decoding information for the specified
   protocol.

4.2.9.  Mapping of the REFERENCE Clause

   If a publicly available reference document exists for this protocol
   it should be listed here.  Typically this will be a URL if possible;
   if not then it will be the name and address of the controlling body.

   The CHILDREN, ADDRESS-FORMAT, and DECODING clauses should limit the
   amount of information which may currently be obtained from an
   'authoritative' document, such as the Assigned Numbers document
   [RFC1700]. Any duplication or paraphrasing of information should be
   brief and consistent with the authoritative document.

   The REFERENCE clause is optional, but should be implemented if an
   authoritative reference exists for the protocol (especially for
   standard protocols).

4.2.10.  Evaluating a Protocol-Identifier INDEX

   The following evaluation is done after protocolDirTable INDEX value
   has been converted into two OCTET STRINGs according to the INDEX
   encoding rules specified in the SMI [RFC1902].

   Protocol-identifiers are evaluated left to right, starting with the
   protocolDirID, which length should be evenly divisible by four. The
   protocolDirParameters length should be exactly one quarter of the
   protocolDirID string length.

   Protocol-identifier parsing starts with the base layer identifier,
   which must be present, and continues for one or more upper layer
   identifiers, until all OCTETs of the protocolDirID have been used.
   Layers may not be skipped, so identifiers such as 'SNMP over IP' or
   'TCP over anylink' can not exist.

   The base-layer-identifier also contains a 'special function
   identifier' which may apply to the rest of the protocol identifier.

   Wild-carding at the base layer within a protocol encapsulation is the
   only supported special function at this time. Refer to the 'Base
   Protocol Identifiers' section for wildcard encoding rules.

   After the protocol-tree identified in protocolDirID has been parsed,
   each parameter bit-mask (one octet for each 4-octet layer-identifier)
   is evaluated, and applied to the corresponding protocol layer.

   A protocol-identifier label may map to more than one value.  For
   instance, 'ip' maps to 5 distinct values, one for each supported
   encapsulation.  (see the 'IP' section under 'L3 Protocol
   Identifiers'),

   It is important to note that these macros are conceptually expanded
   at implementation time, not at run time.

   If all the macros are expanded completely by substituting all
   possible values of each label for each child protocol, a list of all
   possible protocol-identifiers is produced.  So 'ip' would result in 5
   distinct protocol-identifiers.  Likewise each child of 'ip' would map
   to at least 5 protocol-identifiers, one for each encapsulation (e.g.
   ip over ether2, ip over LLC, etc.).

5.  Protocol Identifier Macros

   The following PROTOCOL IDENTIFIER macros can be used to construct
   protocolDirID and protocolDirParameters strings.

   The sections defining protocol examples are intended to grow over
   subsequent releases. Minimal protocol support is included at this
   time.  (Refer to section 3.2 for details on the protocol macro update
   procedure.)

   An identifier is encoded by constructing the base-identifier, then
   adding one layer-identifier for each encapsulated protocol.

5.1.  Base Identifier Encoding

   The first layer encapsulation is called the base identifier and it
   contains optional protocol-function information and the base layer
   (e.g.  MAC layer) enumeration value used in this protocol identifier.

   The base identifier is encoded as four octets as shown in figure 2.

          Fig. 2
     base-identifier format
     +---+---+---+---+
     |   |   |   |   |
     | f |op1|op2| m |
     |   |   |   |   |
     +---+---+---+---+ octet
     | 1 | 1 | 1 | 1 | count

   The first octet ('f') is the special function code, found in table
   4.1.  The next two octets ('op1' and 'op2') are operands for the
   indicated function. If not used, an operand must be set to zero.  The
   last octet, 'm', is the enumerated value for a particular base layer
   encapsulation, found in table 4.2.  All four octets are encoded in
   network-byte-order.

5.1.1.  Protocol Identifier Functions

   The base layer identifier contains information about any special
   functions to perform during collections of this protocol, as well as
   the base layer encapsulation identifier.

   The first three octets of the identifier contain the function code
   and two optional operands. The fourth octet contains the particular
   base layer encapsulation used in this protocol (fig. 2).

     Table 4.1  Assigned Protocol Identifier Functions
     -------------------------------------------------

           Function     ID    Param1               Param2
           ----------------------------------------------------
           none          0    not used (0)         not used (0)
           wildcard      1    not used (0)         not used (0)

5.1.1.1.  Function 0: No-op

   If the function ID field (1st octet) is equal to zero, the the 'op1'
   and 'op2' fields (2nd and 3rd octets) must also be equal to zero.
   This special value indicates that no functions are applied to the
   protocol identifier encoded in the remaining octets. The identifier
   represents a normal protocol encapsulation.

5.1.1.2.  Function 1: Protocol Wildcard Function

   The wildcard function (function-ID = 1), is used to aggregate
   counters, by using a single protocol value to indicate potentially
   many base layer encapsulations of a particular network layer
   protocol. A protocolDirEntry of this type will match any base-layer
   encapsulation of the same protocol.

   The 'op1' field (2nd octet) is not used and must be set to zero.

   The 'op2' field (3rd octet) is not used and must be set to zero.

   Each wildcard protocol identifier must be defined in terms of a 'base
   encapsulation'. This should be as 'standard' as possible for
   interoperability purposes. If an encapsulation over 'ether2' is
   permitted, than this should be used as the base encapsulation.

   The agent may also be requested to count some or all of the
   individual encapsulations for the same protocols, in addition to
   wildcard counting.  Note that the RMON-2 MIB [RMON2] does not require
   that agents maintain counters for multiple encapsulations of the same
   protocol.  It is an implementation-specific matter as to how an agent
   determines which protocol combinations to allow in the
   protocolDirTable at any given time.

5.2.  Base Layer Protocol Identifiers

   The base layer is mandatory, and defines the base encapsulation of
   the packet and any special functions for this identifier.

   There are no suggested protocolDirParameters bits for the base layer.

   The suggested ProtocolDirDescr field for the base layer is given by
   the corresponding "Name" field in the table 4.1 below. However,
   implementations are only required to use the appropriate integer
   identifier values.

   For most base layer protocols, the protocolDirType field should
   contain bits set for  the 'hasChildren(0)' and
   'addressRecognitionCapable(1)' attributes.  However, the special
   'ianaAssigned' base layer should have no parameter or attribute bits
   set.

   By design, only 255 different base layer encapsulations are
   supported.  There are five base encapsulation values defined at this
   time. New base encapsulations (e.g. for new media types) are expected
   to be added over time.

     Table 4.2  Base Layer Encoding Values
     --------------------------------------

           Name          ID
           ------------------
           ether2        1
           llc           2
           snap          3
           vsnap         4
           ianaAssigned    5

5.2.1.  Ether2 Encapsulation

ether2 PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "DIX Ethernet, also called Ethernet-II."
    CHILDREN
       "The Ethernet-II type field is used to select child protocols.
       This is a 16-bit field.  Child protocols are deemed to start at
       the first octet after this type field.

       Children of this protocol are encoded as [ 0.0.0.1 ], the
       protocol identifier for 'ether2' followed by [ 0.0.a.b ] where
       'a' and 'b' are the network byte order encodings of the MSB and
       LSB of the Ethernet-II type value.

       For example, a protocolDirID-fragment value of:
          0.0.0.1.0.0.8.0 defines IP encapsulated in ether2.

       Children of are named as 'ether2' followed by the type field
       value in hexadecimal.  The above example would be declared as:
          ether2 0x0800"
    ADDRESS-FORMAT
       "Ethernet addresses are 6 octets in network order."
    DECODING
       "Only type values greater than or equal to 1500 decimal indicate
       Ethernet-II frames; lower values indicate 802.3 encapsulation
       (see below)."
    REFERENCE
       "A Standard for the Transmission of IP Datagrams over Ethernet
       Networks; RFC 894 [RFC894].

       The authoritative list of Ether Type values is identified by the
       URL:

          ftp://ftp.isi.edu/in-notes/iana/assignments/ethernet-numbers"
    ::= { 1 }

5.2.2.  LLC Encapsulation

llc PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "The LLC (802.2) protocol."
    CHILDREN
       "The LLC SSAP and DSAP (Source/Dest Service Access Points) are
       used to select child protocols.  Each of these is one octet long,
       although the least significant bit is a control bit and should be
       masked out in most situations.  Typically SSAP and DSAP (once
       masked) are the same for a given protocol - each end implicitly
       knows whether it is the server or client in a client/server
       protocol.  This is only a convention, however, and it is possible
       for them to be different.  The SSAP is matched against child
       protocols first.  If none is found then the DSAP is matched
       instead.  The child protocol is deemed to start at the first
       octet after the LLC control field(s).

       Children of 'llc' are encoded as [ 0.0.0.2 ], the protocol
       identifier component for LLC followed by [ 0.0.0.a ] where 'a' is
       the SAP value which maps to the child protocol.  For example, a
       protocolDirID-fragment value of:
          0.0.0.2.0.0.0.240

       defines NetBios over LLC.

       Children are named as 'llc' followed by the SAP value in
       hexadecimal.  So the above example would have been named:
          llc 0xf0"
    ADDRESS-FORMAT
       "The address consists of 6 octets of MAC address in network
       order.  Source routing bits should be stripped out of the address
       if present."
    DECODING
       "Notice that LLC has a variable length protocol header; there are
       always three octets (DSAP, SSAP, control).  Depending on the
       value of the control bits in the DSAP, SSAP and control fields
       there may be an additional octet of control information.

       LLC can be present on several different media.  For 802.3 and
       802.5 its presence is mandated (but see ether2 and raw802.3
       encapsulations).  For 802.5 there is no other link layer
       protocol.

       Notice also that the raw802.3 link layer protocol may take
       precedence over this one in a protocol specific manner such that
       it may not be possible to utilize all LSAP values if raw802.3 is
       also present."
    REFERENCE
       "The authoritative list of LLC LSAP values is controlled by the
       IEEE Registration Authority:
       IEEE Registration Authority
          c/o Iris Ringel
          IEEE Standards Dept
          445 Hoes Lane, P.O. Box 1331
          Piscataway, NJ 08855-1331
          Phone +1 908 562 3813
          Fax: +1 908 562 1571"
    ::= { 2 }

5.2.3.  SNAP over LLC (OUI=000) Encapsulation

snap PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "The Sub-Network Access Protocol (SNAP) is layered on top of LLC
       protocol, allowing Ethernet-II protocols to be run over a media
       restricted to LLC."
    CHILDREN
       "Children of 'snap' are identified by Ethernet-II type values;
       the SNAP PID (Protocol Identifier) field is used to select the
       appropriate child.  The entire SNAP protocol header is consumed;
       the child protocol is assumed to start at the next octet after
       the PID.

       Children of 'snap' are encoded as [ 0.0.0.3 ], the protocol
       identifier for 'snap', followed by [ 0.0.a.b ] where 'a' and 'b'
       are the MSB and LSB of the Ethernet-II type value.  For example,
       a protocolDirID-fragment value of:
          0.0.0.3.0.0.8.0

       defines the IP/SNAP protocol.

       Children of this protocol are named 'snap' followed by the
       Ethernet-II type value in hexadecimal.  The above example would
       be named:

          snap 0x0800"

    ADDRESS-FORMAT
         "The address format for SNAP is the same as that for LLC"
    DECODING
       "SNAP is only present over LLC.  Both SSAP and DSAP will be 0xAA
       and a single control octet will be present.  There are then three
       octets of OUI and two octets of PID.  For this encapsulation the
       OUI must be 0x000000 (see 'vsnap' below for non-zero OUIs)."
    REFERENCE
       "SNAP Identifier values are assigned by the IEEE Standards
       Office.  The address is:
               IEEE Registration Authority
               c/o Iris Ringel
               IEEE Standards Dept
               445 Hoes Lane, P.O. Box 1331
               Piscataway, NJ 08855-1331
               Phone +1 908 562 3813
               Fax: +1 908 562 1571"
    ::= { 3 }

5.2.4.  SNAP over LLC (OUI != 000) Encapsulation

vsnap PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "This pseudo-protocol handles all SNAP packets which do not have
       a zero OUI.  See 'snap' above for details of those that do."
    CHILDREN
       "Children of 'vsnap' are selected by the 3 octet OUI; the PID is
       not parsed; child protocols are deemed to start with the first
       octet of the SNAP PID field, and continue to the end of the
       packet.

       Children of 'vsnap' are encoded as [ 0.0.0.4 ], the protocol
       identifier for 'vsnap', followed by [ 0.a.b.c.0.0.d.e ] where
       'a', 'b' and 'c' are the 3 octets of the OUI field in network
       byte order. This is in turn followed by the 16-bit EtherType
       value, where the 'd' and 'e' represent the MSB and LSB of the
       EtherType, respectively.

       For example, a protocolDirID-fragment value of:
         0.0.0.4.0.8.0.7.0.0.128.155
       defines the AppleTalk Phase 2 protocol over vsnap.

       Note that two protocolDirParameters octets must be present in
       protocolDirTable INDEX values for 'vsnap' protocols.  The first
       protocolDirParameters octet defines the actual parameters. The
       second protocolDirParameters octet is not used and must be set to
       zero.

       Children are named as 'vsnap(<OUI>) <ethertype>', where the
       '<OUI>' field is represented as 3 octets in hexadecimal notation
       or the ASCII string associated with the OUI value. The
       <ethertype> field is represented by the 2 byte EtherType value in
       hexadecimal notation. So the above example would be named:

         'vsnap(0x080007) 0x809b' or 'vsnap(apple) 0x809b'"
    ADDRESS-FORMAT
       "The LLC address format is inherited by 'vsnap'.  See the 'llc'
       protocol identifier for more details."
    DECODING
       "Same as for 'snap' except the OUI is non-zero."
    REFERENCE
       "SNAP Identifier values are assigned by the IEEE Standards
       Office.  The address is:
               IEEE Registration Authority
               c/o Iris Ringel
               IEEE Standards Dept
               445 Hoes Lane, P.O. Box 1331
               Piscataway, NJ 08855-1331
               Phone +1 908 562 3813
               Fax: +1 908 562 1571"
    ::= { 4 }

5.2.5.  IANA Assigned Protocols

ianaAssigned PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "This branch contains protocols which do not conform easily to
       the hierarchical format utilized in the other link layer
       branches.  Usually, such a protocol 'almost' conforms to a
       particular 'well-known' identifier format, but additional
       criteria are used (e.g. configuration-based), making protocol
       identification difficult or impossible by examination of
       appropriate network traffic.  preventing the any 'well-known'
       protocol-identifier macro from being used.

       Sometimes well-known protocols are simply remapped to a different
       port number by one or more venders (e.g. SNMP). These protocols
       can be identified with the 'user-extensibility' feature of the
       protocolDirTable, and do not need special IANA
       assignments.

       A centrally located list of these enumerated protocols must be
       maintained to insure interoperability.
       (See section 3.2 for details on the document update procedure.)
       Support for new link-layers will be added explicitly, and only
       protocols which cannot possibly be represented in a better way
       will be considered as 'ianaEnumerated' protocols.

       IANA assigned protocols are identified by the base-layer-selector
       value [ 0.0.0.5 ], followed by the four octets [ a.b.c.d ] of the
       integer value corresponding to the particular IANA protocol.

       Do not create children of this protocol unless you are sure that
       they cannot be handled by the more conventional link layers
       above."
    CHILDREN
       "Children of this protocol are identified by implementation-
       specific means, described (as best as possible) in the 'DECODING'
       clause within the protocol-variant-identifier macro for each
       enumerated protocol.

       For example, a protocolDirID-fragment value of:
          0.0.0.5.0.0.0.1

       defines the IPX protocol encapsulated directly in 802.3

       Children are named 'ianaAssigned' followed by the name or numeric
       of the particular IANA assigned protocol. The above
       example would be named:

          'ianaAssigned 1' or 'ianaAssigned ipxOverRaw8023'"

    DECODING
       "The 'ianaAssigned' base layer is a pseudo-protocol and is not
       decoded."
    REFERENCE
       "Refer to individual PROTOCOL-IDENTIFIER macros for information
       on each child of the IANA assigned protocol."
    ::= { 5 }

5.2.5.1.  IANA Assigned Protocol Identifiers

   The following protocol-variant-identifier macro declarations are used
   to identify the RMONMIB IANA assigned protocols in a proprietary way,
   by simple enumeration. Note that an additional four-octet layer
   identifier may be used for some enumerations (as with the 'vsnap'
   base-layer identifier). Refer to the 'CHILDREN' clause in the
   protocol-identifier macro for a particular protocol to determine the
   number of octets in the 'ianaAssigned' layer-identifier.

ipxOverRaw8023 PROTOCOL-IDENTIFIER
    VARIANT-OF  "ipx"
    PARAMETERS  { }
    ATTRIBUTES  { }
    DESCRIPTION
       "This pseudo-protocol describes an encapsulation of IPX over
       802.3, without a type field.

       Refer to the macro for IPX for additional information about this
       protocol."
    DECODING
       "Whenever the 802.3 header indicates LLC a set of protocol
       specific tests needs to be applied to determine whether this is a
       'raw8023' packet or a true 802.2 packet.  The nature of these
       tests depends on the active child protocols for 'raw8023' and is
       beyond the scope of this document."
    ::= { ianaAssigned 1 }

5.3.  L3: Children of Base Protocol Identifiers

   Network layer protocol identifier macros contain additional
   information about the network layer, and is found immediately
   following a base layer-identifier in a protocol identifier.

   The ProtocolDirParameters supported at the network layer are
   'countsFragments(0)', and 'tracksSessions(1). An agent may choose to
   implement a subset of these parameters.

   The protocol-name should be used for the ProtocolDirDescr field.  The
   ProtocolDirType ATTRIBUTES used at the network layer are
   'hasChildren(0)' and 'addressRecognitionCapable(1)'. Agents may
   choose to implement a subset of these attributes for each protocol,
   and therefore limit which tables the indicated protocol can be
   present (e.g.  protocol distribution, host, and matrix tables)..

   The following protocol-identifier macro declarations are given for
   example purposes only. They are not intended to constitute an
   exhaustive list or an authoritative source for any of the protocol

   information given.  However, any protocol that can encapsulate other
   protocols must be documented here in order to encode the children
   identifiers into protocolDirID strings. Leaf protocols should be
   documented as well, but an implementation can identify a leaf
   protocol even if it isn't listed here (as long as the parent is
   documented).

5.3.1.  IP

ip PROTOCOL-IDENTIFIER
    PARAMETERS {
          countsFragments(0)  -- This parameter applies to all child
                              -- protocols.
    }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "The protocol identifiers for the Internet Protocol (IP). Note
       that IP may be encapsulated within itself, so more than one of
       the following identifiers may be present in a particular
       protocolDirID string."
    CHILDREN
       "Children of 'ip' are selected by the value in the Protocol field
       (one octet), as defined in the PROTOCOL NUMBERS table within the
       Assigned Numbers Document.

       The value of the Protocol field is encoded in an octet string as
       [ 0.0.0.a ], where 'a' is the protocol field .

       Children of 'ip' are encoded as [ 0.0.0.a ], and named as 'ip a'
       where 'a' is the protocol field value. For example, a
       protocolDirID-fragment value of:
          0.0.0.1.0.0.8.0.0.0.0.1

       defines an encapsulation of ICMP (ether2.ip.icmp)"
    ADDRESS-FORMAT
       "4 octets of the IP address, in network byte order.  Each ip
       packet contains two addresses, the source address and the
       destination address."
    DECODING
       "Note: ether2/ip/ipip4/udp is a different protocolDirID than
       ether2/ip/udp, as identified in the protocolDirTable. As such,
       two different local protocol index values will be assigned by the
       agent. E.g. (full INDEX values shown):
        ether2/ip/ipip4/udp 16.0.0.0.1.0.0.8.0.0.0.0.4.0.0.0.17.4.0.0.0.0
        ether2/ip/udp       12.0.0.0.1.0.0.8.0.0.0.0.17.3.0.0.0 "

    REFERENCE
       "RFC 791 [RFC791] defines the Internet Protocol; The following
       URL defines the authoritative repository for the PROTOCOL NUMBERS
       Table:

          ftp://ftp.isi.edu/in-notes/iana/assignments/protocol-numbers"
    ::= {
          ether2 0x0800,
          llc 0x06,
          snap 0x0800,
          ip 4,
          ip 94
    }

5.3.2.  IPX

ipx PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
         hasChildren(0),
         addressRecognitionCapable(1)
    }
    DESCRIPTION
       "Novell IPX"
    CHILDREN
       "Children of IPX are defined by the 16 bit value of the
       Destination Socket field.  The value is encoded into an octet
       string as [ 0.0.a.b ], where 'a' and 'b' are the network byte
       order encodings of the MSB and LSB of the destination socket
       field."
    ADDRESS-FORMAT
       "4 bytes of Network number followed by the 6 bytes Host address
       each in network byte order".
    REFERENCE
       "The IPX protocol is defined by the Novell Corporation

       A complete description of IPX may be secured at the following
       address:
              Novell, Inc.
              122 East 1700 South
              P. O. Box 5900
              Provo, Utah 84601 USA
              800 526 5463
              Novell Part # 883-000780-001"
    ::= {
        ether2     0x8137,           -- 0.0.129.55
        llc        0xe0e003,         -- 0.224.224.3
        snap       0x8137,           -- 0.0.129.55
        ianaAssigned 0x1               -- 0.0.0.1   (ipxOverRaw8023)
    }

5.3.3.  ARP

arp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "An Address Resolution Protocol message (request or response).
       This protocol does not include Reverse ARP (RARP) packets, which
       are counted separately."
    REFERENCE
       "RFC 826 [RFC826] defines the Address Resolution Protocol."
    ::= {
        ether2 0x806,   -- [ 0.0.8.6 ]
        snap 0x806
    }

5.3.4.  IDP

idp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
         hasChildren(0),
         addressRecognitionCapable(1)
    }
    DESCRIPTION
       "Xerox IDP"
    CHILDREN
       "Children of IDP are defined by the 8 bit value of the Packet
       type field.  The value is encoded into an octet string as [
       0.0.0.a ], where 'a' is the value of the packet type field in
       network byte order."

    ADDRESS-FORMAT
       "4 bytes of Network number followed by the 6 bytes Host address
       each in network byte order".
    REFERENCE
       "Xerox Corporation, Document XNSS 028112, 1981"
    ::=  {
       ether2  0x600,     -- [ 0.0.6.0 ]
       snap    0x600
    }

5.3.5.  AppleTalk ARP

atalkarp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "AppleTalk Address Resolution Protocol."
    REFERENCE
       "AppleTalk Phase 2 Protocol Specification, document ADPA
       #C0144LL/A."
    ::=   {
      ether2 0x80f3,  --  [ 0.0.128.243 ]
      vsnap(0x080007) 0x80f3
    }

5.3.6.  AppleTalk

atalk PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
        hasChildren(0),
        addressRecognitionCapable(1)
    }
    DESCRIPTION
       "AppleTalk Protocol."
    CHILDREN
       "Children of ATALK are defined by the 8 bit value of the DDP type
       field.  The value is encoded into an octet string as [ 0.0.0.a ],
       where 'a' is the value of the DDP type field in network byte
       order."
    ADDRESS-FORMAT
       "2 bytes of Network number followed by 1 byte of node id each in
       network byte order".

    REFERENCE
       "AppleTalk Phase 2 Protocol Specification, document ADPA
       #C0144LL/A."
    ::=   {
      ether2  0x809b,   -- [ 0.0.128.155 ]
      vsnap(0x080007) 0x809b
    }

5.4.  L4: Children of L3 Protocols

5.4.1.  ICMP

icmp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Internet Message Control Protocol."
    REFERENCE
       "RFC 792 [RFC792] defines the Internet Control Message Protocol."
    ::= { ip 1 }

5.4.2.  TCP

tcp  PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
         hasChildren(0)
    }
    DESCRIPTION
       "Transmission Control Protocol."
    CHILDREN
       "Children of TCP are identified by the 16 bit Destination Port
       value as specified in RFC 793. They are encoded as [ 0.0.a.b],
       where 'a' is the MSB and 'b' is the LSB of the Destination Port
       value. Both bytes are encoded in network byte order.  For
       example, a protocolDirId-fragment of:
           0.0.0.1.0.0.8.0.0.0.0.6.0.0.0.23

       identifies an encapsulation of the telnet protocol
       (ether2.ip.tcp.telnet)"
    REFERENCE
       "RFC 793 [RFC793] defines the Transmission Control Protocol.

       The following URL defines the authoritative repository for
       reserved and registered TCP port values:

         ftp://ftp.isi.edu/in-notes/iana/assignments/port-numbers"
    ::=  { ip 6 }

5.4.3.  UDP

udp  PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
         hasChildren(0)
    }
    DESCRIPTION
       "User Datagram Protocol."
    CHILDREN
       "Children of UDP are identified by the 16 bit Destination Port
       value as specified in RFC 768. They are encoded as [ 0.0.a.b ],
       where 'a' is the MSB and 'b' is the LSB of the Destination Port
       value. Both bytes are encoded in network byte order.  For
       example, a protocolDirId-fragment of:
           0.0.0.1.0.0.8.0.0.0.0.17.0.0.0.161

       identifies an encapsulation of SNMP (ether2.ip.udp.snmp)"
    REFERENCE
       "RFC 768 [RFC768] defines the User Datagram Protocol.

       The following URL defines the authoritative repository for
       reserved and registered UDP port values:

         ftp://ftp.isi.edu/in-notes/iana/assignments/port-numbers"
   ::= { ip 17 }

5.5.  L5: Application Layer Protocols

5.5.1.  FTP

5.5.1.1.  FTP-DATA

ftp-data PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "The File Transfer Protocol Data Port; the FTP Server process
       default data-connection port. "
    REFERENCE
       "RFC 959 [RFC959] defines the File Transfer Protocol.  Refer to
       section 3.2 of [RFC959] for details on FTP data connections."
    ::= { tcp 20 }

5.5.1.2.  FTP Control

ftp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "The File Transfer Protocol Control Port; An FTP client initiates
       an FTP control connection by sending FTP commands from user port
       (U) to this port."
    REFERENCE
       "RFC 959 [RFC959] defines the File Transfer Protocol."
    ::= { tcp 21 }

5.5.2.  Telnet

telnet PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "The Telnet Protocol; The purpose of the TELNET Protocol is to
       provide a fairly general, bi-directional, eight-bit byte oriented
       communications facility.  Its primary goal is to allow a standard
       method of interfacing terminal devices and terminal-oriented
       processes to each other. "
    REFERENCE
       "RFC 854 [RFC854] defines the basic Telnet Protocol."
    ::= { tcp 23 }

5.5.3.  SMTP

smtp PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "The Simple Mail Transfer Protocol; SMTP control and data
       messages are sent on this port."
    REFERENCE
       "RFC 821 [RFC821] defines the basic Simple Mail Transfer
       Protocol."
    ::= { tcp 25 }

5.5.4.  DNS

domain PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Domain Name Service Protocol; DNS may be transported by either
       UDP [RFC768] or TCP [RFC793].  If the transport is UDP, DNS
       requests restricted to 512 bytes in length may be sent to this
       port."
    REFERENCE
       "RFC 1035 [RFC1035] defines the Bootstrap Protocol."
    ::= { udp 53,
          tcp 53  }

5.5.5.  BOOTP

5.5.5.1.  Bootstrap Server Protocol

bootps PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Bootstrap Protocol Server Protocol; BOOTP Clients send requests
       (usually broadcast) to the bootps port."
    REFERENCE
       "RFC 951 [RFC951] defines the Bootstrap Protocol."
    ::= { udp 67 }

5.5.5.2.  Bootstrap Client Protocol

bootpc PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Bootstrap Protocol Client Protocol; BOOTP Server replies are
       sent to the BOOTP Client using this destination port."
    REFERENCE
       "RFC 951 [RFC951] defines the Bootstrap Protocol."
    ::= { udp 68 }

5.5.6.  TFTP

tftp PROTOCOL-IDENTIFIER
    PARAMETERS {
        tracksSessions(1)
    }
    ATTRIBUTES { }
    DESCRIPTION
       "Trivial File Transfer Protocol; Only the first packet of each
       TFTP transaction will be sent to port 69. If the tracksSessions
       attribute is set, then packets for each TFTP transaction will be
       attributed to tftp, instead of the unregistered port numbers that
       will be encoded in subsequent packets."
    REFERENCE
       "RFC 1350 [RFC1350] defines the TFTP Protocol (revision 2); RFC
       1782 [RFC1782] defines TFTP Option Extensions; RFC 1783 [RFC1783]
       defines the TFTP Blocksize Option; RFC 1784 [RFC1784] defines
       TFTP Timeout Interval and Transfer Size Options."

    ::= { udp 69 }

5.5.7.  HTTP

www-http PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Hypertext Transfer Protocol; "
    REFERENCE
       "RFC 1945 [RFC1945] defines the Hypertext Transfer Protocol
       (HTTP/1.0)."
    ::= { tcp 80 }

5.5.8.  POP3

pop3 PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Post Office Protocol -- Version 3. Clients establish connections
       with POP3 servers by using this destination port number."
    REFERENCE
       "RFC 1725 [RFC1725] defines Version 3 of the Post Office
       Protocol."
    ::= { tcp 110 }

5.5.9.  SUNRPC

sunrpc PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES {
                hasChildren(0)   -- port mapper function numbers
        }
    DESCRIPTION
       "SUN Remote Procedure Call Protocol. Port mapper function
       requests are sent to this destination port."
    CHILDREN
       Specific RPC functions are represented as children of the sunrpc
       protocol. Each 'RPC function protocol' is identified by its
       function number assignment. RPC function number assignments are
       defined by different naming authorities, depending of the
       function identifier value.
       From [RFC1831]:

       Program numbers are given out in groups of hexadecimal 20000000
       (decimal 536870912) according to the following chart:

                     0 - 1fffffff   defined by rpc@sun.com
              20000000 - 3fffffff   defined by user
              40000000 - 5fffffff   transient
              60000000 - 7fffffff   reserved
              80000000 - 9fffffff   reserved
              a0000000 - bfffffff   reserved
              c0000000 - dfffffff   reserved
              e0000000 - ffffffff   reserved

       Children of 'sunrpc' are encoded as [ 0.0.0.111], the protocol
       identifier component for 'sunrpc', followed by [ a.b.c.d ], where
       a.b.c.d is the 32 bit binary RPC program number encoded in
       network byte order.  For example, a protocolDirID-fragment value
       of:
           0.0.0.111.0.1.134.163

       defines the NFS function (and protocol).

       Children are named as 'sunrpc' followed by the RPC function
       number in base 10 format. For example, NFS would be named:
           'sunrpc 100003'.
    REFERENCE
       "RFC 1831 [RFC1831] defines the Remote Procedure Call Protocol
       Version 2.  The authoritative list of RPC Functions is identified
       by the URL:
           ftp://ftp.isi.edu/in-notes/iana/assignments/sun-rpc-numbers"
    ::= { udp 111 }

5.5.10.  NFS

nfs  PROTOCOL-IDENTIFIER
    PARAMETERS {
                countsFragments(0)
        }
    ATTRIBUTES { }
    DESCRIPTION
       "Sun Network File System (NFS);"
    DECODING
       "The first packet in an NFS transaction is sent to the port-
       mapper, and therefore decoded statically by monitoring RFC
       portmap requests [RFC1831]. Any subsequent NFS fragments must be
       decoded and correctly identified by 'remembering' the port
       assignments used in each RPC function call (as identified
       according to the procedures in the RPC Specification Version 2
       [RFC1831]).

       The 'countsFragments(0)' PARAMETER bit is used to indicate
       whether the probe can (and should) monitor portmapper activity to
       correctly attribute all NFS packets."
    REFERENCE
       "The NFS Version 3 Protocol Specification is defined in RFC 1813
       [RFC1813]."
    ::= {
        sunrpc 100003           --  [0.1.134.163]
    }

5.5.11.  SNMP

5.5.11.1.  SNMP Request/Response

snmp  PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Simple Network Management Protocol. Includes SNMPv1 and SNMPv2
       protocol versions. Does not include SNMP trap packets."
    REFERENCE
       "The SNMP SMI is defined in RFC 1902 [RFC1902]. The SNMP
       protocol is defined in RFC 1905 [RFC1905].  Transport mappings
       are defined in RFC 1906 [RFC1906]; RFC 1420 (SNMP over IPX)
       [RFC1420]; RFC 1419 (SNMP over AppleTalk) [RFC1419]."
    ::= {
        udp 161,
        ipx 0x900f,   -- [ 0.0.144.15 ]
        atalk 8
    }

5.5.11.2.  SNMP Trap

snmptrap PROTOCOL-IDENTIFIER
    PARAMETERS { }
    ATTRIBUTES { }
    DESCRIPTION
       "Simple Network Management Protocol Trap Port."
    REFERENCE
       "The SNMP SMI is defined in RFC 1902 [RFC1902]. The SNMP
       protocol is defined in RFC 1905 [RFC1905].  Transport mappings
       are defined in RFC 1906 [RFC1906]; RFC 1420 (SNMP over IPX)
       [RFC1420]; RFC 1419 (SNMP over AppleTalk) [RFC1419]."
    ::= {
        udp 162,
        ipx 0x9010,
        atalk 9
    }

6.  Acknowledgements

   This document was produced by the IETF RMONMIB Working Group.

   The authors wish to thank the following people for their
   contributions to this document:

        Anil Singhal
        Frontier Software Development, Inc.

        Jeanne Haney
        Bay Networks

        Dan Hansen
        Network General Corp.

7.  References

[RFC768]
     Postel, J., "User Datagram Protocol", STD 6, RFC 768,
     USC/Information Sciences Institute, August 1980.

[RFC791]
     Postel, J., ed., "Internet Protocol - DARPA Internet Program
     Protocol Specification", STD 5, RFC 791, USC/Information Sciences
     Institute, September 1981.

[RFC792]
     Postel, J., "Internet Control Message Protocol - DARPA Internet
     Program Protocol Specification", STD 5, RFC 792, USC/Information
     Sciences Institute, September 1981.

[RFC793]
     Postel, J., "Transmission Control Protocol - DARPA Internet Program
     Protocol Specification", STD 5, RFC 793, USC/Information Sciences
     Institute, September 1981.

[RFC821]
     Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821,
     USC/Information Sciences Institute, August 1982.

[RFC826]
     Plummer, D., "An Ethernet Address Resolution Protocol or
     "Converting Network Protocol Addresses to 48-bit Ethernet Addresses
     for Transmission on Ethernet Hardware", STD 37, RFC 826, MIT-LCS,
     November 1982.

[RFC854]
     Postel, J. and J. Reynolds, "Telnet Protocol Specification",
     STD 8, RFC 854, ISI, May 1983.

[RFC894]
     Hornig, C., "A Standard for the Transmission of IP Datagrams over
     Ethernet Networks", RFC 894, Symbolics, April 1984.

[RFC951]
     Croft, B., and J. Gilmore, "BOOTSTRAP Protocol (BOOTP)", RFC 951,
     Stanford and SUN Microsytems, September 1985.

[RFC959]
     Postel, J., and J. Reynolds, "File Transfer Protocol", STD 8,
     RFC 959, USC/Information Sciences Institute, October 1985.

[RFC1035]
     Mockapetris, P., "Domain Names - Implementation and Specification",
     STD 13, RFC 1035, USC/Information Sciences Institute, November
     1987.

[RFC1157]
     Case, J., M. Fedor, M. Schoffstall, J. Davin, "Simple Network
     Management Protocol", STD 15, RFC 1157, SNMP Research,
     Performance Systems International, MIT Laboratory for Computer
     Science, May 1990.

[RFC1213]
     McCloghrie, K., and M. Rose, Editors, "Management Information Base
     for Network Management of TCP/IP-based internets: MIB-II", STD 17,
     RFC 1213, Hughes LAN Systems, Performance Systems International,
     March 1991.

[RFC1350]
     Sollins, K., "TFTP Protocol (revision 2)", RFC 1350, MIT, July
     1992.

[RFC1419]
     Minshall, G., and M.  Ritter, "SNMP over AppleTalk", RFC 1419,
     Novell, Inc., Apple Computer, Inc., March 1993.

[RFC1420]
     Bostock, S., "SNMP over IPX", RFC 1420, Novell, Inc., March 1993.

[RFC1700]
     Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1700,
     USC/Information Sciences Institute, October 1994.

[RFC1725]
     Myers, J., and M. Rose, "Post Office Protocol - Version 3", RFC
     1725, Carnegie Mellon, Dover Beach Consulting, November 1994.

[RFC1757]
     S. Waldbusser, "Remote Network Monitoring MIB", RFC 1757, Carnegie
     Mellon University, February 1995.

[RFC1782]
     Malkin, G., and A. Harkin, T "TFTP Option Extension", RFC 1782,
     Xylogics, Inc., Hewlett Packard Co., March 1995.

[RFC1783]
     Malkin, G., and A. Harkin, T "TFTP BlockOption Option", RFC 1783,
     Xylogics, Inc., Hewlett Packard Co., March 1995.

[RFC1784]
     Malkin, G., and A. Harkin, "TFTP Timeout Interval and Transfer Size
     Options", RFC 1784, Xylogics, Inc., Hewlett Packard Co., March
     1995.

[RFC1800]
     Postel, J., Editor, "Internet Official Protocol Standards", STD 1,
     RFC 1920, IAB, March 1996.

[RFC1831]
     Srinivasan, R., "Remote Procedure Call Protocol Version 2", RFC
     1831, Sun Microsystems, Inc., August 1995.

[RFC1902]
     SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
     S. Waldbusser, "Structure of Management Information for version 2
     of the Simple Network Management Protocol (SNMPv2)", RFC 1902,
     January 1996.

[RFC1903]
     SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
     S. Waldbusser, "Textual Conventions for version 2 of the Simple
     Network Management Protocol (SNMPv2)", RFC 1903, January 1996.

[RFC1904]
     SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
     S. Waldbusser, "Conformance Statements for version 2 of the Simple
     Network Management Protocol (SNMPv2)", RFC 1904, January 1996.

[RFC1905]
     SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
     S. Waldbusser, "Protocol Operations for version 2 of the Simple
     Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

[RFC1906]
     SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S.
     Waldbusser, "Transport Mappings for Version 2 of the Simple Network
     Management Protocol (SNMPv2)", RFC 1906, January 1996.

[RFC1945]
     Berners-Lee, T., and R. Fielding, "Hypertext Transfer Protocol --
     HTTP/1.0", RFC 1945, MIT/UC-Irvine, November 1995.

[RMON2]
     S. Waldbusser, "Remote Network Monitoring MIB (RMON-2)", draft-
     ietf-rmonmib-rmon2-03.txt, International Network Services, January
     1996.

8.  Security Considerations

   Security issues are not discussed in this memo.

9.  Authors' Addresses

   Andy Bierman
   Cisco Systems, Inc.
   170 West Tasman Drive
   San Jose, CA 95134

   Phone: 408-527-3711
   EMail: abierman@cisco.com

   Robin Iddon
   3Com/AXON
   40/50 Blackfrias Street
   Edinburgh, UK

   Phone: +44 131.558.3888
   EMail: robin_iddon@3mail.3com.com

 

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