<pre>Network Working Group                                    K. Norseth, Ed.
Request for Comments: 4188                            L-3 Communications
Obsoletes: <a href="./rfc1493">1493</a>                                             E. Bell, Ed.
Category: Standards Track                            3Com Europe Limited
                                                          September 2005


               <span class="h1">Definitions of Managed Objects for Bridges</span>

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.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP-based internets.
   In particular, it defines objects for managing MAC bridges based on
   the IEEE 802.1D-1998 standard between Local Area Network (LAN)
   segments.  Provisions are made for the support of transparent
   bridging.  Provisions are also made so that these objects apply to
   bridges connected by subnetworks other than LAN segments.

   The MIB module presented in this memo is a translation of the
   BRIDGE-MIB defined in <a href="./rfc1493">RFC 1493</a> to the SMIv2 syntax.

   This memo obsoletes <a href="./rfc1493">RFC 1493</a>.
















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Table of Contents

   <a href="#section-1">1</a>. The Internet-Standard Management Framework ......................<a href="#page-2">2</a>
   <a href="#section-2">2</a>. Conventions .....................................................<a href="#page-2">2</a>
   <a href="#section-3">3</a>. Overview ........................................................<a href="#page-3">3</a>
      <a href="#section-3.1">3.1</a>. Structure of the MIB Module ................................<a href="#page-3">3</a>
           <a href="#section-3.1.1">3.1.1</a>. The dot1dBase Subtree ...............................<a href="#page-6">6</a>
           <a href="#section-3.1.2">3.1.2</a>. The dot1dStp Subtree ................................<a href="#page-6">6</a>
           <a href="#section-3.1.3">3.1.3</a>. The dot1dSr Subtree .................................<a href="#page-6">6</a>
           <a href="#section-3.1.4">3.1.4</a>. The dot1dTp Subtree .................................<a href="#page-6">6</a>
           <a href="#section-3.1.5">3.1.5</a>. The dot1dStatic Subtree .............................<a href="#page-6">6</a>
      <a href="#section-3.2">3.2</a>. Relationship to Other MIB Modules ..........................<a href="#page-6">6</a>
           <a href="#section-3.2.1">3.2.1</a>. Relationship to the SNMPv2-MIB ......................<a href="#page-7">7</a>
           <a href="#section-3.2.2">3.2.2</a>. Relationship to the IF-MIB ..........................<a href="#page-7">7</a>
   <a href="#section-4">4</a>. Definitions .....................................................<a href="#page-8">8</a>
   <a href="#section-5">5</a>. IANA Considerations ............................................<a href="#page-39">39</a>
   <a href="#section-6">6</a>. Security Considerations ........................................<a href="#page-39">39</a>
   <a href="#section-7">7</a>. Acknowledgements ...............................................<a href="#page-40">40</a>
   <a href="#section-8">8</a>. Contact Information ............................................<a href="#page-41">41</a>
   <a href="#section-9">9</a>. Changes from <a href="./rfc1493">RFC 1493</a> ..........................................<a href="#page-42">42</a>
   <a href="#section-10">10</a>. References ....................................................<a href="#page-42">42</a>
      <a href="#section-10.1">10.1</a>. Normative References .....................................<a href="#page-42">42</a>
      <a href="#section-10.2">10.2</a>. Informative References ...................................<a href="#page-43">43</a>

<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>.  The Internet-Standard Management Framework</span>

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to <a href="./rfc3410#section-7">section&nbsp;7 of
   RFC 3410</a> [<a href="./rfc3410" title="&quot;Introduction and Applicability Statements for Internet- Standard Management Framework&quot;">RFC3410</a>].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).  This memo specifies a MIB
   module that is compliant to the SMIv2, which is described in STD 58,
   <a href="./rfc2578">RFC 2578</a> [<a href="./rfc2578" title="&quot;Structure of Management Information Version 2 (SMIv2)&quot;">RFC2578</a>], STD 58, <a href="./rfc2579">RFC 2579</a> [<a href="./rfc2579" title="&quot;Textual Conventions for SMIv2&quot;">RFC2579</a>] and STD 58, <a href="./rfc2580">RFC 2580</a>
   [<a href="./rfc2580" title="&quot;Conformance Statements for SMIv2&quot;">RFC2580</a>].

<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>.  Conventions</span>

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL", when they appear in this document, are to be interpreted
   as described in <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a> [<a href="./rfc2119" title="&quot;Key words for use in RFCs to Indicate Requirement Levels&quot;">RFC2119</a>].






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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>.  Overview</span>

   A common device present in many networks is the Bridge.  This device
   is used to connect Local Area Network segments below the network
   layer.

   There are two major modes defined for this bridging: transparent and
   source route.  The transparent method of bridging is defined in the
   IEEE 802.1D specification [<a href="#ref-IEEE8021D" title="&quot;ANSI/IEEE Standard 802.1D-1998 MAC Bridges&quot;">IEEE8021D</a>].  This memo defines those
   objects needed for the management of a bridging entity that operates
   in the transparent mode, as well as some objects that apply to all
   types of bridges.

   To be consistent with IAB directives and good engineering practices,
   an explicit attempt was made to keep this MIB module as simple as
   possible.  This was accomplished by applying the following criteria
   to objects proposed for inclusion:

   1. Start with a small set of essential objects and add only as
      further objects are needed.

   2. Require that objects be essential for either fault or
      configuration management.

   3. Consider evidence of current use and/or utility.

   4. Limit the total number of objects.

   5. Exclude objects that are simply derivable from others in this or
      other MIB modules.

   6. Avoid causing critical sections to be heavily instrumented.  The
      guideline that was followed is one counter per critical section
      per layer.

<span class="h3"><a class="selflink" id="section-3.1" href="#section-3.1">3.1</a>  Structure of the MIB Module</span>

   Objects in this MIB module are arranged into subtrees.  Each subtree
   is organized as a set of related objects.  The overall structure and
   assignment of objects to their subtrees is shown below.  Where
   appropriate, the corresponding IEEE 802.1D [<a href="#ref-IEEE8021D" title="&quot;ANSI/IEEE Standard 802.1D-1998 MAC Bridges&quot;">IEEE8021D</a>] management
   object name is also included.









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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   Bridge MIB Name                  IEEE 802.1D Name

   dot1dBridge
     dot1dBase
       BridgeAddress                Bridge.BridgeAddress
       NumPorts                     Bridge.NumberOfPorts
       Type
       PortTable
         Port                       BridgePort.PortNumber
         IfIndex
         Circuit
         DelayExceededDiscards        .DiscardTransitDelay
         MtuExceededDiscards          .DiscardOnError
     dot1dStp
       ProtocolSpecification
       Priority                     SpanningTreeProtocol
                                      .BridgePriority
       TimeSinceTopologyChange        .TimeSinceTopologyChange
       TopChanges                     .TopologyChangeCount
       DesignatedRoot                 .DesignatedRoot
       RootCost                       .RootCost
       RootPort                       .RootPort
       MaxAge                         .MaxAge
       HelloTime                      .HelloTime
       HoldTime                       .HoldTime
       ForwardDelay                   .ForwardDelay
       BridgeMaxAge                   .BridgeMaxAge
       BridgeHelloTime                .BridgeHelloTime
       BridgeForwardDelay             .BridgeForwardDelay
       PortTable
         Port                        SpanningTreeProtocolPort
                                       .PortNumber
         Priority                      .PortPriority
         State                         .SpanningTreeState
         Enable
         PathCost                      .PortPathCost
         DesignatedRoot                .DesignatedRoot
         DesignatedCost                .DesignatedCost
         DesignatedBridge              .DesignatedBridge
         DesignatedPort                .DesignatedPort
         ForwardTransitions










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     dot1dTp
       LearnedEntryDiscards          BridgeFilter.DatabaseSize
                                       .NumDynamic,NumStatic
       AgingTime                     BridgeFilter.AgingTime
       FdbTable
         Address
         Port
         Status
       PortTable
         Port
         MaxInfo
         InFrames                    BridgePort.FramesReceived
         OutFrames                     .ForwardOutbound
         InDiscards                    .DiscardInbound
     dot1dStatic
       StaticTable
         Address
         ReceivePort
         AllowedToGoTo
         Status

   The following IEEE 802.1D management objects have not been included
   in the BRIDGE-MIB module for the indicated reasons.

   IEEE 802.1D Object              Disposition

   Bridge.BridgeName               Same as sysDescr (SNMPv2-MIB)
   Bridge.BridgeUpTime             Same as sysUpTime (SNMPv2-MIB)
   Bridge.PortAddresses            Same as ifPhysAddress (IF-MIB)
   BridgePort.PortName             Same as ifDescr (IF-MIB)
   BridgePort.PortType             Same as ifType (IF-MIB)
   BridgePort.RoutingType          Derivable from the implemented
                                   subtrees

   SpanningTreeProtocol
       .BridgeIdentifier           Combination of dot1dStpPriority
                                   and dot1dBaseBridgeAddress
       .TopologyChange             Since this is transitory, it
                                   is not considered useful.
   SpanningTreeProtocolPort
       .Uptime                     Same as ifLastChange (IF-MIB)
       .PortIdentifier             Combination of dot1dStpPort
                                   and dot1dStpPortPriority
       .TopologyChangeAcknowledged Since this is transitory, it
                                   is not considered useful.
       .DiscardLackOfBuffers       Redundant





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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   Transmission Priority           These objects are not required
                                   as per the Pics Proforma and
                                   are not considered useful.
       .TransmissionPriorityName
       .OutboundUserPriority
       .OutboundAccessPriority

<span class="h4"><a class="selflink" id="section-3.1.1" href="#section-3.1.1">3.1.1</a>  The dot1dBase Subtree</span>

   This subtree contains the objects that are applicable to all types of
   bridges.

<span class="h4"><a class="selflink" id="section-3.1.2" href="#section-3.1.2">3.1.2</a>  The dot1dStp Subtree</span>

   This subtree contains the objects that denote the bridge's state with
   respect to the Spanning Tree Protocol.  If a node does not implement
   the Spanning Tree Protocol, this subtree will not be implemented.

<span class="h4"><a class="selflink" id="section-3.1.3" href="#section-3.1.3">3.1.3</a>  The dot1dSr Subtree</span>

   This subtree contains the objects that describe the entity's state
   with respect to source route bridging.  This subtree described in <a href="./rfc1525">RFC</a>
   <a href="./rfc1525">1525</a> [<a href="./rfc1525" title="&quot;Definitions of Managed Objects for Source Routing Bridges&quot;">RFC1525</a>] is applicable only to source route bridging.

<span class="h4"><a class="selflink" id="section-3.1.4" href="#section-3.1.4">3.1.4</a>  The dot1dTp Subtree</span>

   This subtree contains objects that describe the entity's state with
   respect to transparent bridging.  If transparent bridging is not
   supported, this subtree will not be implemented.  This subtree is
   applicable to transparent-only and SRT bridges.

<span class="h4"><a class="selflink" id="section-3.1.5" href="#section-3.1.5">3.1.5</a>  The dot1dStatic Subtree</span>

   This subtree contains objects that describe the entity's state with
   respect to destination-address filtering.  If destination-address
   filtering is not supported, this subtree will not be implemented.
   This subtree is applicable to any type of bridge that performs
   destination-address filtering.

<span class="h3"><a class="selflink" id="section-3.2" href="#section-3.2">3.2</a>  Relationship to Other MIB Modules</span>

   As described above, some IEEE 802.1D management objects have not been
   included in this MIB module because they overlap with objects in
   other MIB modules that are applicable to a bridge implementing this
   MIB module.






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<span class="h4"><a class="selflink" id="section-3.2.1" href="#section-3.2.1">3.2.1</a>  Relationship to the SNMPv2-MIB</span>

   The SNMPv2-MIB [<a href="./rfc3418" title="&quot;Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)&quot;">RFC3418</a>] defines objects that are generally
   applicable to managed devices.  These objects apply to the device as
   a whole, irrespective of whether the device's sole functionality is
   bridging, or whether bridging is only a subset of the device's
   functionality.

   As explained in <a href="#section-3.1">Section 3.1</a>, full support for the 802.1D management
   objects requires that the SNMPv2-MIB objects sysDescr and sysUpTime
   be implemented.  Note that compliance with the current SNMPv2-MIB
   module requires additional objects and notifications to be
   implemented, as specified in <a href="./rfc3418">RFC 3418</a> [<a href="./rfc3418" title="&quot;Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)&quot;">RFC3418</a>].

<span class="h4"><a class="selflink" id="section-3.2.2" href="#section-3.2.2">3.2.2</a>  Relationship to the IF-MIB</span>

   The IF-MIB [<a href="./rfc2863" title="&quot;The Interfaces Group MIB&quot;">RFC2863</a>] defines managed objects for managing network
   interfaces.  A network interface is thought of as being attached to a
   `subnetwork'.  Note that this term is not to be confused with
   `subnet', which refers to an addressing partitioning scheme used in
   the Internet suite of protocols.  The term 'segment' is used in this
   memo to refer to such a subnetwork, whether it be an Ethernet
   segment, a 'ring', a WAN link, or even an X.25 virtual circuit.

   As explained in <a href="#section-3.1">Section 3.1</a>, full support for the 802.1D management
   objects requires that the IF-MIB objects ifIndex, ifType, ifDescr,
   ifPhysAddress, and ifLastChange are implemented.  Note that
   compliance to the current IF-MIB module requires additional objects
   and notifications to be implemented as specified in <a href="./rfc2863">RFC 2863</a>
   [<a href="./rfc2863" title="&quot;The Interfaces Group MIB&quot;">RFC2863</a>].

   Implicit in this BRIDGE-MIB is the notion of ports on a bridge.  Each
   of these ports is associated with one interface of the 'interfaces'
   subtree, and in most situations, each port is associated with a
   different interface.  However, there are situations in which multiple
   ports are associated with the same interface.  An example of such a
   situation would be several ports, each corresponding, one-to-one,
   with several X.25 virtual circuits that are all on the same
   interface.

   Each port is uniquely identified by a port number.  A port number has
   no mandatory relationship to an interface number, but in the simple
   case, a port number will have the same value as the corresponding
   interface's interface number.  Port numbers are in the range
   (1..dot1dBaseNumPorts).






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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   Some entities perform other functionalities as well as bridging
   through the sending and receiving of data on their interfaces.  In
   such situations, only a subset of the data sent/received on an
   interface is within the domain of the entity's bridging
   functionality.  This subset is considered to be delineated according
   to a set of protocols, with some protocols being bridged, and other
   protocols not being bridged.  For example, in an entity that
   exclusively performs bridging, all protocols would be considered as
   bridged, whereas in an entity that performs IP routing on IP
   datagrams and only bridges other protocols, only the non-IP data
   would be considered as having been bridged.

   Thus, this BRIDGE-MIB (and in particular, its counters) are
   applicable only to that subset of the data on an entity's interfaces
   that is sent/received for a protocol being bridged.  All such data is
   sent/received via the ports of the bridge.

<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>.  Definitions</span>

   BRIDGE-MIB DEFINITIONS ::= BEGIN

   -- ---------------------------------------------------------- --
   -- MIB for IEEE 802.1D devices
   -- ---------------------------------------------------------- --
   IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
       Counter32, Integer32, TimeTicks, mib-2
           FROM SNMPv2-SMI
       TEXTUAL-CONVENTION, MacAddress
           FROM SNMPv2-TC
       MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
           FROM SNMPv2-CONF
       InterfaceIndex FROM IF-MIB
       ;

   dot1dBridge MODULE-IDENTITY
       LAST-UPDATED "200509190000Z"
       ORGANIZATION "IETF Bridge MIB Working Group"
       CONTACT-INFO
           "Email: bridge-mib@ietf.org

                    K.C. Norseth (Editor)
                    L-3 Communications
               Tel: +1 801-594-2809
             Email: kenyon.c.norseth@L-3com.com
            Postal: 640 N. 2200 West.
                    Salt Lake City, Utah 84116-0850




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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


                    Les Bell (Editor)
                    3Com Europe Limited
             Phone: +44 1442 438025
             Email: elbell@ntlworld.com
            Postal: 3Com Centre, Boundary Way
                    Hemel Hempstead
                    Herts.  HP2 7YU
                    UK

            Send comments to &lt;bridge-mib@ietf.org&gt;"
       DESCRIPTION
           "The Bridge MIB module for managing devices that support
           IEEE 802.1D.

           Copyright (C) The Internet Society (2005).  This version of
           this MIB module is part of <a href="./rfc4188">RFC 4188</a>; see the RFC itself for
           full legal notices."
       REVISION     "200509190000Z"
       DESCRIPTION
            "Third revision, published as part of <a href="./rfc4188">RFC 4188</a>.

            The MIB module has been converted to SMIv2 format.
            Conformance statements have been added and some
            description and reference clauses have been updated.

            The object dot1dStpPortPathCost32 was added to
            support IEEE 802.1t and the permissible values of
            dot1dStpPriority and dot1dStpPortPriority have been
            clarified for bridges supporting IEEE 802.1t or
            IEEE 802.1w.

            The interpretation of dot1dStpTimeSinceTopologyChange
            has been clarified for bridges supporting the Rapid
            Spanning Tree Protocol (RSTP)."
       REVISION     "199307310000Z"
       DESCRIPTION
            "Second revision, published as part of <a href="./rfc1493">RFC 1493</a>."
       REVISION     "199112310000Z"
       DESCRIPTION
            "Initial revision, published as part of <a href="./rfc1286">RFC 1286</a>."
       ::= { mib-2 17 }


   -- ---------------------------------------------------------- --
   -- Textual Conventions
   -- ---------------------------------------------------------- --

   BridgeId ::= TEXTUAL-CONVENTION



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       STATUS      current
       DESCRIPTION
           "The Bridge-Identifier, as used in the Spanning Tree
           Protocol, to uniquely identify a bridge.  Its first two
           octets (in network byte order) contain a priority value,
           and its last 6 octets contain the MAC address used to
           refer to a bridge in a unique fashion (typically, the
           numerically smallest MAC address of all ports on the
           bridge)."
       SYNTAX      OCTET STRING (SIZE (8))

   Timeout ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "d"
       STATUS      current
       DESCRIPTION
           "A Spanning Tree Protocol (STP) timer in units of 1/100
           seconds.  Several objects in this MIB module represent
           values of timers used by the Spanning Tree Protocol.
           In this MIB, these timers have values in units of
           hundredths of a second (i.e., 1/100 secs).

           These timers, when stored in a Spanning Tree Protocol's
           BPDU, are in units of 1/256 seconds.  Note, however, that
           802.1D-1998 specifies a settable granularity of no more
           than one second for these timers.  To avoid ambiguity,
           a conversion algorithm is defined below for converting
           between the different units, which ensures a timer's
           value is not distorted by multiple conversions.

           To convert a Timeout value into a value in units of
           1/256 seconds, the following algorithm should be used:

               b = floor( (n * 256) / 100)

           where:
               floor   =  quotient [ignore remainder]
               n is the value in 1/100 second units
               b is the value in 1/256 second units

           To convert the value from 1/256 second units back to
           1/100 seconds, the following algorithm should be used:

               n = ceiling( (b * 100) / 256)

           where:
               ceiling = quotient [if remainder is 0], or
                         quotient + 1 [if remainder is nonzero]
               n is the value in 1/100 second units



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               b is the value in 1/256 second units

           Note: it is important that the arithmetic operations are
           done in the order specified (i.e., multiply first,
           divide second)."
       SYNTAX      Integer32

   -- ---------------------------------------------------------- --
   -- subtrees in the Bridge MIB
   -- ---------------------------------------------------------- --

   dot1dNotifications  OBJECT IDENTIFIER ::= { dot1dBridge 0 }

   dot1dBase           OBJECT IDENTIFIER ::= { dot1dBridge 1 }
   dot1dStp            OBJECT IDENTIFIER ::= { dot1dBridge 2 }

   dot1dSr             OBJECT IDENTIFIER ::= { dot1dBridge 3 }
   -- documented in <a href="./rfc1525">RFC 1525</a>

   dot1dTp             OBJECT IDENTIFIER ::= { dot1dBridge 4 }
   dot1dStatic         OBJECT IDENTIFIER ::= { dot1dBridge 5 }

   -- Subtrees used by Bridge MIB Extensions:
   --      pBridgeMIB  MODULE-IDENTITY   ::= { dot1dBridge 6 }
   --      qBridgeMIB  MODULE-IDENTITY   ::= { dot1dBridge 7 }
   -- Note that the practice of registering related MIB modules
   -- below dot1dBridge has been discouraged since there is no
   -- robust mechanism to track such registrations.

   dot1dConformance    OBJECT IDENTIFIER ::= { dot1dBridge 8 }

   -- ---------------------------------------------------------- --
   -- the dot1dBase subtree
   -- ---------------------------------------------------------- --
   -- Implementation of the dot1dBase subtree is mandatory for all
   -- bridges.
   -- ---------------------------------------------------------- --

   dot1dBaseBridgeAddress OBJECT-TYPE

       SYNTAX      MacAddress
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The MAC address used by this bridge when it must be
           referred to in a unique fashion.  It is recommended
           that this be the numerically smallest MAC address of
           all ports that belong to this bridge.  However, it is only



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           required to be unique.  When concatenated with
           dot1dStpPriority, a unique BridgeIdentifier is formed,
           which is used in the Spanning Tree Protocol."
       REFERENCE
           "IEEE 802.1D-1998: clauses 14.4.1.1.3 and 7.12.5"
       ::= { dot1dBase 1 }

   dot1dBaseNumPorts OBJECT-TYPE
       SYNTAX      Integer32
       UNITS       "ports"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of ports controlled by this bridging
           entity."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.4.1.1.3"
       ::= { dot1dBase 2 }

   dot1dBaseType OBJECT-TYPE
       SYNTAX      INTEGER {
                       unknown(1),
                       transparent-only(2),
                       sourceroute-only(3),
                       srt(4)
                   }
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "Indicates what type of bridging this bridge can
           perform.  If a bridge is actually performing a
           certain type of bridging, this will be indicated by
           entries in the port table for the given type."
       ::= { dot1dBase 3 }

   -- ---------------------------------------------------------- --
   -- The Generic Bridge Port Table
   -- ---------------------------------------------------------- --
   dot1dBasePortTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF Dot1dBasePortEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table that contains generic information about every
           port that is associated with this bridge.  Transparent,
           source-route, and srt ports are included."
       ::= { dot1dBase 4 }




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   dot1dBasePortEntry OBJECT-TYPE
       SYNTAX      Dot1dBasePortEntry
       MAX-ACCESS  not-accessible
       STATUS      current

       DESCRIPTION
           "A list of information for each port of the bridge."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.4.2, 14.6.1"
       INDEX  { dot1dBasePort }
       ::= { dot1dBasePortTable 1 }

   Dot1dBasePortEntry ::=
       SEQUENCE {
           dot1dBasePort
               Integer32,
           dot1dBasePortIfIndex
               InterfaceIndex,
           dot1dBasePortCircuit
               OBJECT IDENTIFIER,
           dot1dBasePortDelayExceededDiscards
               Counter32,
           dot1dBasePortMtuExceededDiscards
               Counter32
       }

   dot1dBasePort OBJECT-TYPE
       SYNTAX      Integer32 (1..65535)
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The port number of the port for which this entry
           contains bridge management information."
       ::= { dot1dBasePortEntry 1 }

   dot1dBasePortIfIndex OBJECT-TYPE
       SYNTAX      InterfaceIndex
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The value of the instance of the ifIndex object,
           defined in IF-MIB, for the interface corresponding
           to this port."
       ::= { dot1dBasePortEntry 2 }

   dot1dBasePortCircuit OBJECT-TYPE
       SYNTAX      OBJECT IDENTIFIER
       MAX-ACCESS  read-only



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       STATUS      current
       DESCRIPTION
           "For a port that (potentially) has the same value of
           dot1dBasePortIfIndex as another port on the same bridge.
           This object contains the name of an object instance
           unique to this port.  For example, in the case where
           multiple ports correspond one-to-one with multiple X.25
           virtual circuits, this value might identify an (e.g.,
           the first) object instance associated with the X.25
           virtual circuit corresponding to this port.

           For a port which has a unique value of
           dot1dBasePortIfIndex, this object can have the value
           { 0 0 }."
       ::= { dot1dBasePortEntry 3 }

   dot1dBasePortDelayExceededDiscards OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of frames discarded by this port due
           to excessive transit delay through the bridge.  It
           is incremented by both transparent and source
           route bridges."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.6.1.1.3"
       ::= { dot1dBasePortEntry 4 }

   dot1dBasePortMtuExceededDiscards OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of frames discarded by this port due
           to an excessive size.  It is incremented by both
           transparent and source route bridges."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.6.1.1.3"
       ::= { dot1dBasePortEntry 5 }

   -- ---------------------------------------------------------- --
   -- the dot1dStp subtree
   -- ---------------------------------------------------------- --
   -- Implementation of the dot1dStp subtree is optional.  It is
   -- implemented by those bridges that support the Spanning Tree
   -- Protocol.
   -- ---------------------------------------------------------- --



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   dot1dStpProtocolSpecification OBJECT-TYPE
       SYNTAX      INTEGER {
                       unknown(1),
                       decLb100(2),
                       ieee8021d(3)
                   }
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "An indication of what version of the Spanning Tree
           Protocol is being run.  The value 'decLb100(2)'
           indicates the DEC LANbridge 100 Spanning Tree protocol.
           IEEE 802.1D implementations will return 'ieee8021d(3)'.
           If future versions of the IEEE Spanning Tree Protocol
           that are incompatible with the current version
           are released a new value will be defined."
       ::= { dot1dStp 1 }

   dot1dStpPriority OBJECT-TYPE
       SYNTAX      Integer32 (0..65535)
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The value of the write-able portion of the Bridge ID
           (i.e., the first two octets of the (8 octet long) Bridge
           ID).  The other (last) 6 octets of the Bridge ID are
           given by the value of dot1dBaseBridgeAddress.
           On bridges supporting IEEE 802.1t or IEEE 802.1w,
           permissible values are 0-61440, in steps of 4096."
       REFERENCE
           "IEEE 802.1D-1998 clause 8.10.2, Table 8-4,
           IEEE 802.1t clause 8.10.2, Table 8-4, clause 14.3."
       ::= { dot1dStp 2 }

   dot1dStpTimeSinceTopologyChange OBJECT-TYPE
       SYNTAX      TimeTicks
       UNITS       "centi-seconds"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The time (in hundredths of a second) since the
           last time a topology change was detected by the
           bridge entity.
           For RSTP, this reports the time since the tcWhile
           timer for any port on this Bridge was nonzero."
       REFERENCE
           "IEEE 802.1D-1998 clause 14.8.1.1.,
           IEEE 802.1w clause 14.8.1.1."



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       ::= { dot1dStp 3 }

   dot1dStpTopChanges OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The total number of topology changes detected by
           this bridge since the management entity was last
           reset or initialized."
       REFERENCE
           "IEEE 802.1D-1998 clause 14.8.1.1."
       ::= { dot1dStp 4 }

   dot1dStpDesignatedRoot OBJECT-TYPE
       SYNTAX      BridgeId
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The bridge identifier of the root of the spanning
           tree, as determined by the Spanning Tree Protocol,
           as executed by this node.  This value is used as
           the Root Identifier parameter in all Configuration
           Bridge PDUs originated by this node."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.1"
       ::= { dot1dStp 5 }

   dot1dStpRootCost OBJECT-TYPE
       SYNTAX      Integer32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The cost of the path to the root as seen from
           this bridge."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.2"
       ::= { dot1dStp 6 }

   dot1dStpRootPort OBJECT-TYPE
       SYNTAX      Integer32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The port number of the port that offers the lowest
           cost path from this bridge to the root bridge."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.3"



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       ::= { dot1dStp 7 }

   dot1dStpMaxAge OBJECT-TYPE
       SYNTAX      Timeout
       UNITS       "centi-seconds"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The maximum age of Spanning Tree Protocol information
           learned from the network on any port before it is
           discarded, in units of hundredths of a second.  This is
           the actual value that this bridge is currently using."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.4"
       ::= { dot1dStp 8 }

   dot1dStpHelloTime OBJECT-TYPE
       SYNTAX      Timeout
       UNITS       "centi-seconds"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The amount of time between the transmission of
           Configuration bridge PDUs by this node on any port when
           it is the root of the spanning tree, or trying to become
           so, in units of hundredths of a second.  This is the
           actual value that this bridge is currently using."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.5"
       ::= { dot1dStp 9 }

   dot1dStpHoldTime OBJECT-TYPE
       SYNTAX      Integer32
       UNITS       "centi-seconds"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "This time value determines the interval length
           during which no more than two Configuration bridge
           PDUs shall be transmitted by this node, in units
           of hundredths of a second."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.14"
       ::= { dot1dStp 10 }

   dot1dStpForwardDelay OBJECT-TYPE
       SYNTAX      Timeout
       UNITS       "centi-seconds"



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       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "This time value, measured in units of hundredths of a
           second, controls how fast a port changes its spanning
           state when moving towards the Forwarding state.  The
           value determines how long the port stays in each of the
           Listening and Learning states, which precede the
           Forwarding state.  This value is also used when a
           topology change has been detected and is underway, to
           age all dynamic entries in the Forwarding Database.
           [Note that this value is the one that this bridge is
           currently using, in contrast to
           dot1dStpBridgeForwardDelay, which is the value that this
           bridge and all others would start using if/when this
           bridge were to become the root.]"
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.6"
       ::= { dot1dStp 11 }

   dot1dStpBridgeMaxAge OBJECT-TYPE
       SYNTAX      Timeout (600..4000)
       UNITS       "centi-seconds"
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The value that all bridges use for MaxAge when this
           bridge is acting as the root.  Note that 802.1D-1998
           specifies that the range for this parameter is related
           to the value of dot1dStpBridgeHelloTime.  The
           granularity of this timer is specified by 802.1D-1998 to
           be 1 second.  An agent may return a badValue error if a
           set is attempted to a value that is not a whole number
           of seconds."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.8"
       ::= { dot1dStp 12 }

   dot1dStpBridgeHelloTime OBJECT-TYPE
       SYNTAX      Timeout (100..1000)
       UNITS       "centi-seconds"
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The value that all bridges use for HelloTime when this
           bridge is acting as the root.  The granularity of this
           timer is specified by 802.1D-1998 to be 1 second.  An
           agent may return a badValue error if a set is attempted



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           to a value that is not a whole number of seconds."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.9"
       ::= { dot1dStp 13 }

   dot1dStpBridgeForwardDelay OBJECT-TYPE
       SYNTAX      Timeout (400..3000)
       UNITS       "centi-seconds"
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The value that all bridges use for ForwardDelay when
           this bridge is acting as the root.  Note that
           802.1D-1998 specifies that the range for this parameter
           is related to the value of dot1dStpBridgeMaxAge.  The
           granularity of this timer is specified by 802.1D-1998 to
           be 1 second.  An agent may return a badValue error if a
           set is attempted to a value that is not a whole number
           of seconds."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.3.10"
       ::= { dot1dStp 14 }

   -- ---------------------------------------------------------- --
   -- The Spanning Tree Port Table
   -- ---------------------------------------------------------- --

   dot1dStpPortTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF Dot1dStpPortEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table that contains port-specific information
           for the Spanning Tree Protocol."
       ::= { dot1dStp 15 }

   dot1dStpPortEntry OBJECT-TYPE
       SYNTAX      Dot1dStpPortEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A list of information maintained by every port about
           the Spanning Tree Protocol state for that port."
       INDEX   { dot1dStpPort }
       ::= { dot1dStpPortTable 1 }

   Dot1dStpPortEntry ::=
       SEQUENCE {



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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


           dot1dStpPort
               Integer32,
           dot1dStpPortPriority
               Integer32,
           dot1dStpPortState
               INTEGER,
           dot1dStpPortEnable
               INTEGER,
           dot1dStpPortPathCost
               Integer32,
           dot1dStpPortDesignatedRoot
               BridgeId,
           dot1dStpPortDesignatedCost
               Integer32,
           dot1dStpPortDesignatedBridge
               BridgeId,
           dot1dStpPortDesignatedPort
               OCTET STRING,
           dot1dStpPortForwardTransitions
               Counter32,
           dot1dStpPortPathCost32
               Integer32
       }

   dot1dStpPort OBJECT-TYPE
       SYNTAX      Integer32 (1..65535)
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The port number of the port for which this entry
           contains Spanning Tree Protocol management information."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.8.2.1.2"
       ::= { dot1dStpPortEntry 1 }

   dot1dStpPortPriority OBJECT-TYPE
       SYNTAX      Integer32 (0..255)
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The value of the priority field that is contained in
           the first (in network byte order) octet of the (2 octet
           long) Port ID.  The other octet of the Port ID is given
           by the value of dot1dStpPort.
           On bridges supporting IEEE 802.1t or IEEE 802.1w,
           permissible values are 0-240, in steps of 16."
       REFERENCE
           "IEEE 802.1D-1998 clause 8.10.2, Table 8-4,



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           IEEE 802.1t clause 8.10.2, Table 8-4, clause 14.3."
       ::= { dot1dStpPortEntry 2 }

   dot1dStpPortState OBJECT-TYPE
       SYNTAX      INTEGER {
                       disabled(1),
                       blocking(2),
                       listening(3),
                       learning(4),
                       forwarding(5),
                       broken(6)
                   }
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The port's current state, as defined by application of
           the Spanning Tree Protocol.  This state controls what
           action a port takes on reception of a frame.  If the
           bridge has detected a port that is malfunctioning, it
           will place that port into the broken(6) state.  For
           ports that are disabled (see dot1dStpPortEnable), this
           object will have a value of disabled(1)."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.2"
       ::= { dot1dStpPortEntry 3 }

   dot1dStpPortEnable OBJECT-TYPE
       SYNTAX      INTEGER {
                       enabled(1),
                       disabled(2)
                   }
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The enabled/disabled status of the port."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.2"
       ::= { dot1dStpPortEntry 4 }

   dot1dStpPortPathCost OBJECT-TYPE
       SYNTAX      Integer32 (1..65535)
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The contribution of this port to the path cost of
           paths towards the spanning tree root which include
           this port.  802.1D-1998 recommends that the default
           value of this parameter be in inverse proportion to



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           the speed of the attached LAN.

           New implementations should support dot1dStpPortPathCost32.
           If the port path costs exceeds the maximum value of this
           object then this object should report the maximum value,
           namely 65535.  Applications should try to read the
           dot1dStpPortPathCost32 object if this object reports
           the maximum value."
       REFERENCE "IEEE 802.1D-1998: clause 8.5.5.3"
           ::= { dot1dStpPortEntry 5 }

   dot1dStpPortDesignatedRoot OBJECT-TYPE
       SYNTAX      BridgeId
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The unique Bridge Identifier of the Bridge
           recorded as the Root in the Configuration BPDUs
           transmitted by the Designated Bridge for the
           segment to which the port is attached."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.4"
       ::= { dot1dStpPortEntry 6 }

   dot1dStpPortDesignatedCost OBJECT-TYPE
       SYNTAX      Integer32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The path cost of the Designated Port of the segment
           connected to this port.  This value is compared to the
           Root Path Cost field in received bridge PDUs."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.5"
       ::= { dot1dStpPortEntry 7 }

   dot1dStpPortDesignatedBridge OBJECT-TYPE
       SYNTAX      BridgeId
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The Bridge Identifier of the bridge that this
           port considers to be the Designated Bridge for
           this port's segment."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.6"
       ::= { dot1dStpPortEntry 8 }




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   dot1dStpPortDesignatedPort OBJECT-TYPE
       SYNTAX      OCTET STRING (SIZE (2))
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The Port Identifier of the port on the Designated
           Bridge for this port's segment."
       REFERENCE
           "IEEE 802.1D-1998: clause 8.5.5.7"
       ::= { dot1dStpPortEntry 9 }

   dot1dStpPortForwardTransitions OBJECT-TYPE
       SYNTAX      Counter32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of times this port has transitioned
           from the Learning state to the Forwarding state."
       ::= { dot1dStpPortEntry 10 }

   dot1dStpPortPathCost32 OBJECT-TYPE
       SYNTAX      Integer32 (1..200000000)
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The contribution of this port to the path cost of
           paths towards the spanning tree root which include
           this port.  802.1D-1998 recommends that the default
           value of this parameter be in inverse proportion to
           the speed of the attached LAN.

           This object replaces dot1dStpPortPathCost to support
           IEEE 802.1t."
       REFERENCE
           "IEEE 802.1t clause 8.10.2, Table 8-5."
       ::= { dot1dStpPortEntry 11 }

   -- ---------------------------------------------------------- --
   -- the dot1dTp subtree
   -- ---------------------------------------------------------- --
   -- Implementation of the dot1dTp subtree is optional.  It is
   -- implemented by those bridges that support the transparent
   -- bridging mode.  A transparent or SRT bridge will implement
   -- this subtree.
   -- ---------------------------------------------------------- --

   dot1dTpLearnedEntryDiscards OBJECT-TYPE
       SYNTAX      Counter32



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       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The total number of Forwarding Database entries that
           have been or would have been learned, but have been
           discarded due to a lack of storage space in the
           Forwarding Database.  If this counter is increasing, it
           indicates that the Forwarding Database is regularly
           becoming full (a condition that has unpleasant
           performance effects on the subnetwork).  If this counter
           has a significant value but is not presently increasing,
           it indicates that the problem has been occurring but is
           not persistent."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.7.1.1.3"
       ::= { dot1dTp 1 }

   dot1dTpAgingTime OBJECT-TYPE
       SYNTAX      Integer32 (10..1000000)
       UNITS       "seconds"
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           "The timeout period in seconds for aging out
           dynamically-learned forwarding information.
           802.1D-1998 recommends a default of 300 seconds."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.7.1.1.3"
       ::= { dot1dTp 2 }


   -- ---------------------------------------------------------- --
   --  The Forwarding Database for Transparent Bridges
   -- ---------------------------------------------------------- --

   dot1dTpFdbTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF Dot1dTpFdbEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table that contains information about unicast
           entries for which the bridge has forwarding and/or
           filtering information.  This information is used
           by the transparent bridging function in
           determining how to propagate a received frame."
       ::= { dot1dTp 3 }

   dot1dTpFdbEntry OBJECT-TYPE



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       SYNTAX      Dot1dTpFdbEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "Information about a specific unicast MAC address
           for which the bridge has some forwarding and/or
           filtering information."
       INDEX   { dot1dTpFdbAddress }
       ::= { dot1dTpFdbTable 1 }

   Dot1dTpFdbEntry ::=
       SEQUENCE {
           dot1dTpFdbAddress
               MacAddress,
           dot1dTpFdbPort
               Integer32,
           dot1dTpFdbStatus
               INTEGER
       }

   dot1dTpFdbAddress OBJECT-TYPE
       SYNTAX      MacAddress
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "A unicast MAC address for which the bridge has
           forwarding and/or filtering information."
       REFERENCE
           "IEEE 802.1D-1998: clause 7.9.1, 7.9.2"
       ::= { dot1dTpFdbEntry 1 }

   dot1dTpFdbPort OBJECT-TYPE
       SYNTAX      Integer32
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "Either the value '0', or the port number of the port on
           which a frame having a source address equal to the value
           of the corresponding instance of dot1dTpFdbAddress has
           been seen.  A value of '0' indicates that the port
           number has not been learned, but that the bridge does
           have some forwarding/filtering information about this
           address (e.g., in the dot1dStaticTable).  Implementors
           are encouraged to assign the port value to this object
           whenever it is learned, even for addresses for which the
           corresponding value of dot1dTpFdbStatus is not
           learned(3)."
       ::= { dot1dTpFdbEntry 2 }



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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   dot1dTpFdbStatus OBJECT-TYPE
       SYNTAX      INTEGER {
                       other(1),
                       invalid(2),
                       learned(3),
                       self(4),
                       mgmt(5)
                   }
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The status of this entry.  The meanings of the
           values are:
               other(1) - none of the following.  This would
                   include the case where some other MIB object
                   (not the corresponding instance of
                   dot1dTpFdbPort, nor an entry in the
                   dot1dStaticTable) is being used to determine if
                   and how frames addressed to the value of the
                   corresponding instance of dot1dTpFdbAddress are
                   being forwarded.
               invalid(2) - this entry is no longer valid (e.g.,
                   it was learned but has since aged out), but has
                   not yet been flushed from the table.
               learned(3) - the value of the corresponding instance
                   of dot1dTpFdbPort was learned, and is being
                   used.
               self(4) - the value of the corresponding instance of
                   dot1dTpFdbAddress represents one of the bridge's
                   addresses.  The corresponding instance of
                   dot1dTpFdbPort indicates which of the bridge's
                   ports has this address.
               mgmt(5) - the value of the corresponding instance of
                   dot1dTpFdbAddress is also the value of an
                   existing instance of dot1dStaticAddress."
       ::= { dot1dTpFdbEntry 3 }

   -- ---------------------------------------------------------- --
   --  Port Table for Transparent Bridges
   -- ---------------------------------------------------------- --

   dot1dTpPortTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF Dot1dTpPortEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table that contains information about every port that
           is associated with this transparent bridge."



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       ::= { dot1dTp 4 }

   dot1dTpPortEntry OBJECT-TYPE
       SYNTAX      Dot1dTpPortEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A list of information for each port of a transparent
           bridge."
       INDEX   { dot1dTpPort }
       ::= { dot1dTpPortTable 1 }

   Dot1dTpPortEntry ::=
       SEQUENCE {
           dot1dTpPort
               Integer32,
           dot1dTpPortMaxInfo
               Integer32,
           dot1dTpPortInFrames
               Counter32,
           dot1dTpPortOutFrames
               Counter32,
           dot1dTpPortInDiscards
               Counter32
       }

   dot1dTpPort OBJECT-TYPE
       SYNTAX      Integer32 (1..65535)
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The port number of the port for which this entry
           contains Transparent bridging management information."
       ::= { dot1dTpPortEntry 1 }

   -- It would be nice if we could use ifMtu as the size of the
   -- largest INFO field, but we can't because ifMtu is defined
   -- to be the size that the (inter-)network layer can use, which
   -- can differ from the MAC layer (especially if several layers
   -- of encapsulation are used).

   dot1dTpPortMaxInfo OBJECT-TYPE
       SYNTAX      Integer32
       UNITS       "bytes"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The maximum size of the INFO (non-MAC) field that



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           this port will receive or transmit."
       ::= { dot1dTpPortEntry 2 }

   dot1dTpPortInFrames OBJECT-TYPE
       SYNTAX      Counter32
       UNITS       "frames"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of frames that have been received by this
           port from its segment.  Note that a frame received on the
           interface corresponding to this port is only counted by
           this object if and only if it is for a protocol being
           processed by the local bridging function, including
           bridge management frames."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.6.1.1.3"
       ::= { dot1dTpPortEntry 3 }

   dot1dTpPortOutFrames OBJECT-TYPE
       SYNTAX      Counter32
       UNITS       "frames"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The number of frames that have been transmitted by this
           port to its segment.  Note that a frame transmitted on
           the interface corresponding to this port is only counted
           by this object if and only if it is for a protocol being
           processed by the local bridging function, including
           bridge management frames."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.6.1.1.3"
       ::= { dot1dTpPortEntry 4 }

   dot1dTpPortInDiscards OBJECT-TYPE
       SYNTAX      Counter32
       UNITS       "frames"
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "Count of received valid frames that were discarded
           (i.e., filtered) by the Forwarding Process."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.6.1.1.3"
       ::= { dot1dTpPortEntry 5 }

   -- ---------------------------------------------------------- --



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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   -- The Static (Destination-Address Filtering) Database
   -- ---------------------------------------------------------- --
   -- Implementation of this subtree is optional.
   -- ---------------------------------------------------------- --

   dot1dStaticTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF Dot1dStaticEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table containing filtering information configured
           into the bridge by (local or network) management
           specifying the set of ports to which frames received
           from specific ports and containing specific destination
           addresses are allowed to be forwarded.  The value of
           zero in this table, as the port number from which frames
           with a specific destination address are received, is
           used to specify all ports for which there is no specific
           entry in this table for that particular destination
           address.  Entries are valid for unicast and for
           group/broadcast addresses."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.7.2"
       ::= { dot1dStatic 1 }

   dot1dStaticEntry OBJECT-TYPE
       SYNTAX      Dot1dStaticEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "Filtering information configured into the bridge by
           (local or network) management specifying the set of
           ports to which frames received from a specific port and
           containing a specific destination address are allowed to
           be forwarded."
       REFERENCE
           "IEEE 802.1D-1998: clause 14.7.2"
       INDEX   { dot1dStaticAddress, dot1dStaticReceivePort }
       ::= { dot1dStaticTable 1 }

   Dot1dStaticEntry ::=
       SEQUENCE {
           dot1dStaticAddress       MacAddress,
           dot1dStaticReceivePort   Integer32,
           dot1dStaticAllowedToGoTo OCTET STRING,
           dot1dStaticStatus        INTEGER
       }




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   dot1dStaticAddress OBJECT-TYPE
       SYNTAX      MacAddress
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The destination MAC address in a frame to which this
           entry's filtering information applies.  This object can
           take the value of a unicast address, a group address, or
           the broadcast address."
       REFERENCE
           "IEEE 802.1D-1998: clause 7.9.1, 7.9.2"
       ::= { dot1dStaticEntry 1 }

   dot1dStaticReceivePort OBJECT-TYPE
       SYNTAX      Integer32 (0..65535)
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "Either the value '0', or the port number of the port
           from which a frame must be received in order for this
           entry's filtering information to apply.  A value of zero
           indicates that this entry applies on all ports of the
           bridge for which there is no other applicable entry."
       ::= { dot1dStaticEntry 2 }

   dot1dStaticAllowedToGoTo OBJECT-TYPE
       SYNTAX      OCTET STRING (SIZE (0..512))
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "The set of ports to which frames received from a
           specific port and destined for a specific MAC address,
           are allowed to be forwarded.  Each octet within the
           value of this object specifies a set of eight ports,
           with the first octet specifying ports 1 through 8, the
           second octet specifying ports 9 through 16, etc.  Within
           each octet, the most significant bit represents the
           lowest numbered port, and the least significant bit
           represents the highest numbered port.  Thus, each port
           of the bridge is represented by a single bit within the
           value of this object.  If that bit has a value of '1',
           then that port is included in the set of ports; the port
           is not included if its bit has a value of '0'.  (Note
           that the setting of the bit corresponding to the port
           from which a frame is received is irrelevant.)  The
           default value of this object is a string of ones of
           appropriate length.




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           The value of this object may exceed the required minimum
           maximum message size of some SNMP transport (484 bytes,
           in the case of SNMP over UDP, see <a href="./rfc3417#section-3.2">RFC 3417, section&nbsp;3.2</a>).
           SNMP engines on bridges supporting a large number of
           ports must support appropriate maximum message sizes."
       ::= { dot1dStaticEntry 3 }

   dot1dStaticStatus OBJECT-TYPE
       SYNTAX      INTEGER {
                       other(1),
                       invalid(2),
                       permanent(3),
                       deleteOnReset(4),
                       deleteOnTimeout(5)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
           "This object indicates the status of this entry.
           The default value is permanent(3).
               other(1) - this entry is currently in use but the
                   conditions under which it will remain so are
                   different from each of the following values.
               invalid(2) - writing this value to the object
                   removes the corresponding entry.
               permanent(3) - this entry is currently in use and
                   will remain so after the next reset of the
                   bridge.
               deleteOnReset(4) - this entry is currently in use
                   and will remain so until the next reset of the
                   bridge.
               deleteOnTimeout(5) - this entry is currently in use
                   and will remain so until it is aged out."
       ::= { dot1dStaticEntry 4 }

   -- ---------------------------------------------------------- --
   -- Notifications for use by Bridges
   -- ---------------------------------------------------------- --
   -- Notifications for the Spanning Tree Protocol
   -- ---------------------------------------------------------- --

   newRoot NOTIFICATION-TYPE
       -- OBJECTS     { }
       STATUS      current
       DESCRIPTION
           "The newRoot trap indicates that the sending agent has
           become the new root of the Spanning Tree; the trap is
           sent by a bridge soon after its election as the new



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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


           root, e.g., upon expiration of the Topology Change Timer,
           immediately subsequent to its election.  Implementation
           of this trap is optional."
       ::= { dot1dNotifications 1 }

   topologyChange NOTIFICATION-TYPE
       -- OBJECTS     { }
       STATUS      current
       DESCRIPTION
           "A topologyChange trap is sent by a bridge when any of
           its configured ports transitions from the Learning state
           to the Forwarding state, or from the Forwarding state to
           the Blocking state.  The trap is not sent if a newRoot
           trap is sent for the same transition.  Implementation of
           this trap is optional."
       ::= { dot1dNotifications 2 }

   -- ---------------------------------------------------------- --
   -- IEEE 802.1D MIB - Conformance Information
   -- ---------------------------------------------------------- --

   dot1dGroups         OBJECT IDENTIFIER ::= { dot1dConformance 1 }
   dot1dCompliances    OBJECT IDENTIFIER ::= { dot1dConformance 2 }

   -- ---------------------------------------------------------- --
   -- units of conformance
   -- ---------------------------------------------------------- --

   -- ---------------------------------------------------------- --
   -- the dot1dBase group
   -- ---------------------------------------------------------- --

   dot1dBaseBridgeGroup OBJECT-GROUP
       OBJECTS {
           dot1dBaseBridgeAddress,
           dot1dBaseNumPorts,
           dot1dBaseType
       }
       STATUS      current
       DESCRIPTION
           "Bridge level information for this device."
       ::= { dot1dGroups 1 }

   dot1dBasePortGroup OBJECT-GROUP
       OBJECTS {
           dot1dBasePort,
           dot1dBasePortIfIndex,
           dot1dBasePortCircuit,



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           dot1dBasePortDelayExceededDiscards,
           dot1dBasePortMtuExceededDiscards
       }
       STATUS      current
       DESCRIPTION
           "Information for each port on this device."
       ::= { dot1dGroups 2 }

   -- ---------------------------------------------------------- --
   -- the dot1dStp group
   -- ---------------------------------------------------------- --

   dot1dStpBridgeGroup OBJECT-GROUP
       OBJECTS {
           dot1dStpProtocolSpecification,
           dot1dStpPriority,
           dot1dStpTimeSinceTopologyChange,
           dot1dStpTopChanges,
           dot1dStpDesignatedRoot,
           dot1dStpRootCost,
           dot1dStpRootPort,
           dot1dStpMaxAge,
           dot1dStpHelloTime,
           dot1dStpHoldTime,
           dot1dStpForwardDelay,
           dot1dStpBridgeMaxAge,
           dot1dStpBridgeHelloTime,
           dot1dStpBridgeForwardDelay
       }
       STATUS      current
       DESCRIPTION
           "Bridge level Spanning Tree data for this device."
       ::= { dot1dGroups 3 }

   dot1dStpPortGroup OBJECT-GROUP
       OBJECTS {
           dot1dStpPort,
           dot1dStpPortPriority,
           dot1dStpPortState,
           dot1dStpPortEnable,
           dot1dStpPortPathCost,
           dot1dStpPortDesignatedRoot,
           dot1dStpPortDesignatedCost,
           dot1dStpPortDesignatedBridge,
           dot1dStpPortDesignatedPort,
           dot1dStpPortForwardTransitions
       }
       STATUS      current



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       DESCRIPTION
           "Spanning Tree data for each port on this device."
       ::= { dot1dGroups 4 }

   dot1dStpPortGroup2 OBJECT-GROUP
       OBJECTS {
           dot1dStpPort,
           dot1dStpPortPriority,
           dot1dStpPortState,
           dot1dStpPortEnable,
           dot1dStpPortDesignatedRoot,
           dot1dStpPortDesignatedCost,
           dot1dStpPortDesignatedBridge,
           dot1dStpPortDesignatedPort,
           dot1dStpPortForwardTransitions,
           dot1dStpPortPathCost32
       }
       STATUS      current
       DESCRIPTION
           "Spanning Tree data for each port on this device."
       ::= { dot1dGroups 5 }

   dot1dStpPortGroup3 OBJECT-GROUP
       OBJECTS {
           dot1dStpPortPathCost32
       }
       STATUS      current
       DESCRIPTION
           "Spanning Tree data for devices supporting 32-bit
            path costs."
       ::= { dot1dGroups 6 }

   -- ---------------------------------------------------------- --
   -- the dot1dTp group
   -- ---------------------------------------------------------- --

   dot1dTpBridgeGroup OBJECT-GROUP
       OBJECTS {
           dot1dTpLearnedEntryDiscards,
           dot1dTpAgingTime
       }
       STATUS      current
       DESCRIPTION
           "Bridge level Transparent Bridging data."
       ::= { dot1dGroups 7 }

   dot1dTpFdbGroup OBJECT-GROUP
       OBJECTS {



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           dot1dTpFdbAddress,
           dot1dTpFdbPort,
           dot1dTpFdbStatus
       }

       STATUS      current
       DESCRIPTION
           "Filtering Database information for the Bridge."
       ::= { dot1dGroups 8 }

   dot1dTpGroup OBJECT-GROUP
       OBJECTS {
           dot1dTpPort,
           dot1dTpPortMaxInfo,
           dot1dTpPortInFrames,
           dot1dTpPortOutFrames,
           dot1dTpPortInDiscards
       }
       STATUS      current
       DESCRIPTION
           "Dynamic Filtering Database information for each port of
           the Bridge."
       ::= { dot1dGroups 9 }

   -- ---------------------------------------------------------- --
   -- The Static (Destination-Address Filtering) Database
   -- ---------------------------------------------------------- --

   dot1dStaticGroup OBJECT-GROUP
       OBJECTS {
           dot1dStaticAddress,
           dot1dStaticReceivePort,
           dot1dStaticAllowedToGoTo,
           dot1dStaticStatus
       }
       STATUS      current
       DESCRIPTION
           "Static Filtering Database information for each port of
           the Bridge."
       ::= { dot1dGroups 10 }

   -- ---------------------------------------------------------- --
   -- The Trap Notification Group
   -- ---------------------------------------------------------- --

   dot1dNotificationGroup NOTIFICATION-GROUP
       NOTIFICATIONS {
           newRoot,



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           topologyChange
       }
       STATUS      current
       DESCRIPTION
           "Group of objects describing notifications (traps)."
       ::= { dot1dGroups 11 }

   -- ---------------------------------------------------------- --
   -- compliance statements
   -- ---------------------------------------------------------- --

   bridgeCompliance1493 MODULE-COMPLIANCE
       STATUS      current
       DESCRIPTION
           "The compliance statement for device support of bridging
           services, as per <a href="./rfc1493">RFC1493</a>."

       MODULE
           MANDATORY-GROUPS {
               dot1dBaseBridgeGroup,
               dot1dBasePortGroup
           }

       GROUP   dot1dStpBridgeGroup
       DESCRIPTION
           "Implementation of this group is mandatory for bridges
           that support the Spanning Tree Protocol."

       GROUP   dot1dStpPortGroup
       DESCRIPTION
           "Implementation of this group is mandatory for bridges
           that support the Spanning Tree Protocol."

       GROUP   dot1dTpBridgeGroup
       DESCRIPTION
           "Implementation of this group is mandatory for bridges
           that support the transparent bridging mode.  A
           transparent or SRT bridge will implement this group."

       GROUP   dot1dTpFdbGroup
       DESCRIPTION
           "Implementation of this group is mandatory for bridges
           that support the transparent bridging mode.  A
           transparent or SRT bridge will implement this group."

       GROUP   dot1dTpGroup
       DESCRIPTION
           "Implementation of this group is mandatory for bridges



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           that support the transparent bridging mode.  A
           transparent or SRT bridge will implement this group."

       GROUP   dot1dStaticGroup
       DESCRIPTION
           "Implementation of this group is optional."

       GROUP dot1dNotificationGroup
       DESCRIPTION
           "Implementation of this group is optional."
       ::= { dot1dCompliances 1 }

   bridgeCompliance4188 MODULE-COMPLIANCE
       STATUS      current
       DESCRIPTION
           "The compliance statement for device support of bridging
           services.  This supports 32-bit Path Cost values and the
           more restricted bridge and port priorities, as per IEEE
           802.1t.

           Full support for the 802.1D management objects requires that
           the SNMPv2-MIB [<a href="./rfc3418" title="&quot;Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)&quot;">RFC3418</a>] objects sysDescr, and sysUpTime, as
           well as the IF-MIB [<a href="./rfc2863" title="&quot;The Interfaces Group MIB&quot;">RFC2863</a>] objects ifIndex, ifType,
           ifDescr, ifPhysAddress, and ifLastChange are implemented."

       MODULE
           MANDATORY-GROUPS {
               dot1dBaseBridgeGroup,
               dot1dBasePortGroup
           }

       GROUP   dot1dStpBridgeGroup
       DESCRIPTION
           "Implementation of this group is mandatory for
           bridges that support the Spanning Tree Protocol."

       OBJECT dot1dStpPriority
       SYNTAX Integer32 (0|4096|8192|12288|16384|20480|24576
                        |28672|32768|36864|40960|45056|49152
                        |53248|57344|61440)
       DESCRIPTION
           "The possible values defined by IEEE 802.1t."

       GROUP   dot1dStpPortGroup2
       DESCRIPTION
           "Implementation of this group is mandatory for
           bridges that support the Spanning Tree Protocol."




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       GROUP   dot1dStpPortGroup3
       DESCRIPTION
           "Implementation of this group is mandatory for bridges
            that support the Spanning Tree Protocol and 32-bit path
            costs.  In particular, this includes devices supporting
            IEEE 802.1t and IEEE 802.1w."

       OBJECT dot1dStpPortPriority
       SYNTAX Integer32 (0|16|32|48|64|80|96|112|128
                        |144|160|176|192|208|224|240)
       DESCRIPTION
           "The possible values defined by IEEE 802.1t."

       GROUP   dot1dTpBridgeGroup
       DESCRIPTION
           "Implementation of this group is mandatory for
           bridges that support the transparent bridging
           mode.  A transparent or SRT bridge will implement
           this group."

       GROUP   dot1dTpFdbGroup
       DESCRIPTION
           "Implementation of this group is mandatory for
           bridges that support the transparent bridging
           mode.  A transparent or SRT bridge will implement
           this group."

       GROUP   dot1dTpGroup
       DESCRIPTION
           "Implementation of this group is mandatory for
           bridges that support the transparent bridging
           mode.  A transparent or SRT bridge will implement
           this group."

       GROUP   dot1dStaticGroup
       DESCRIPTION
           "Implementation of this group is optional."

       GROUP dot1dNotificationGroup
       DESCRIPTION
           "Implementation of this group is optional."

       ::= { dot1dCompliances 2 }

   END






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<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>.  IANA Considerations</span>

   The MIB module in this document uses the following IANA-assigned
   OBJECT IDENTIFIER values that are recorded in the SMI Numbers
   registry:

      Descriptor        OBJECT IDENTIFIER value
      ----------        -----------------------
      dot1dBridge       { mib-2 17 }

<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>.  Security Considerations</span>

   There are a number of management objects defined in this MIB module
   that have a MAX-ACCESS clause of read-write and/or read-create.  Such
   objects may be considered sensitive or vulnerable in some network
   environments.  The support for SET operations in a non-secure
   environment without proper protection can have a negative effect on
   network operations.

   Some of the readable objects in this MIB module (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 and/or NOTIFY access to these objects and possibly
   to even encrypt the values of these objects when sending them over
   the network via SNMP.

   These are the tables and objects and their sensitivity/vulnerability:

   o  The writable objects dot1dStpPriority, dot1dStpBridgeMaxAge,
      dot1dStpBridgeHelloTime, dot1dStpBridgeForwardDelay,
      dot1dStpPortPriority, dot1dStpPortEnable, dot1dStpPortPathCost,
      and dot1dStpPortPathCost32 influence the spanning tree protocol.
      Unauthorized write access to these objects can cause the spanning
      tree protocol to compute other default topologies or it can change
      the speed in which the spanning tree protocol reacts to failures.

   o  The writable object dot1dTpAgingTime controls how fast
      dynamically-learned forwarding information is aged out.  Setting
      this object to a large value may simplify forwarding table
      overflow attacks.

   o  The writable dot1dStaticTable provides a filtering mechanism
      controlling to which ports frames originating from a specific
      source may be forwarded.  Write access to this table can be used
      to turn provisioned filtering off or to add filters to prevent
      rightful use of the network.





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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-40" ></span>
<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   o  The readable objects defined in the BRIDGE-MIB module provide
      information about the topology of a bridged network and the
      attached active stations.  The addresses listed in the
      dot1dTpFdbTable usually reveal information about the manufacturer
      of the MAC hardware, which can be useful information for mounting
      other specific attacks.

   o  The two notifications newRoot and topologyChange are emitted
      during spanning tree computation and may trigger management
      systems to inspect the status of bridges and to recompute internal
      topology information.  Hence, forged notifications may cause
      management systems to perform unnecessary computations and to
      generate additional SNMP traffic directed to the bridges in a
      network.  Therefore, forged notifications may be part of a denial
      of service attack.

   SNMP versions prior to SNMPv3 did not include adequate security.
   Even if the network itself is secure (for example by using IPSec),
   even then, there is no control as to who on the secure network is
   allowed to access and GET/SET (read/change/create/delete) the objects
   in this MIB module.

   It is RECOMMENDED that implementers consider the security features as
   provided by the SNMPv3 framework (see <a href="./rfc3410#section-8">[RFC3410], section&nbsp;8</a>),
   including full support for the SNMPv3 cryptographic mechanisms (for
   authentication and privacy).

   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 an
   instance of this MIB module 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.

<span class="h2"><a class="selflink" id="section-7" href="#section-7">7</a>.  Acknowledgements</span>

   The MIB module presented in this memo is a translation of the
   BRIDGE-MIB defined in [<a href="./rfc1493" title="&quot;Definitions of Managed Objects for Bridges&quot;">RFC1493</a>] to the SMIv2 syntax.  The original
   authors of the SMIv1 module were E. Decker, P. Langille, A.
   Rijsinghani, and K. McCloghrie.  Further acknowledgement is given to
   the members of the original Bridge Working Group in [<a href="./rfc1493" title="&quot;Definitions of Managed Objects for Bridges&quot;">RFC1493</a>].

   This document was produced on behalf of the Bridge MIB Working Group
   in the Operations and Management area of the Internet Engineering
   Task Force.  The editors wish to thank the members of the Bridge MIB
   Working Group, especially Mike MacFadden, John Flick, and Bert
   Visscher for their many comments and suggestions that improved this



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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-41" ></span>
<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   effort.  Juergen Schoenwaelder helped in finalizing the document for
   publication.

<span class="h2"><a class="selflink" id="section-8" href="#section-8">8</a>.  Contact Information</span>

   The original version of this document was the result of significant
   work by four major contributors:

      E. Decker


      P. Langille


      A. Rijsinghan
      Accton Technology Corporation
      5 Mount Royal Ave
      Marlboro, MA 01752
      USA

      K. McCloghrie
      Cisco Systems, Inc.
      170 West Tasman Drive
      San Jose, CA 95134
      USA

   The conversion to the SMIv2 format is based on work done by the
   following two contributors:

      Kenyon C. Norseth
      L-3 Communications
      640 N. 2200 West
      Salt Lake City, Utah 84116-0850
      USA


      E. Bell
      3Com Europe Limited
      3Com Centre, Boundary Way
      Hemel Hempstead Herts. HP2 7YU
      UK










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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-42" ></span>
<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


<span class="h2"><a class="selflink" id="section-9" href="#section-9">9</a>.  Changes from <a href="./rfc1493">RFC 1493</a></span>

   The following changes have been made from <a href="./rfc1493">RFC 1493</a>.

   1. Translated the MIB definitions to use SMIv2.  This includes the
      introduction of conformance statements.  ASN.1 type definitions
      have been converted into textual-conventions and several UNITS
      clauses were added.

   2. The object dot1dStpPortPathCost32 was added to support IEEE
      802.1t.

   3. Permissible values for dot1dStpPriority and dot1dStpPortPriority
      have been clarified for bridges supporting IEEE 802.1t or IEEE
      802.1w.

   4. Interpretation of dot1dStpTimeSinceTopologyChange has been
      clarified for bridges supporting the rapid spanning tree protocol
      (RSTP).

   5. Updated the introductory boilerplate text, the security
      considerations section, and the references to comply with the
      current IETF standards and guidelines.

   6. Updated references to point to newer IEEE 802.1d documents.

   7. Additions and clarifications in various description clauses.

<span class="h2"><a class="selflink" id="section-10" href="#section-10">10</a>.  References</span>

<span class="h3"><a class="selflink" id="section-10.1" href="#section-10.1">10.1</a>  Normative References</span>

   [<a id="ref-RFC2119">RFC2119</a>]   Bradner, S., "Key words for use in RFCs to Indicate
               Requirement Levels", <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a>, March 1997.

   [<a id="ref-RFC2578">RFC2578</a>]   McCloghrie, K., Perkins, D., and J. Schoenwaelder,
               "Structure of Management Information Version 2 (SMIv2)",
               STD 58, <a href="./rfc2578">RFC 2578</a>, April 1999.

   [<a id="ref-RFC2579">RFC2579</a>]   McCloghrie, K., Perkins, D., and J. Schoenwaelder,
               "Textual Conventions for SMIv2", STD 58, <a href="./rfc2579">RFC 2579</a>, April
               1999.

   [<a id="ref-RFC2580">RFC2580</a>]   McCloghrie, K., Perkins, D., and J. Schoenwaelder,
               "Conformance Statements for SMIv2", STD 58, <a href="./rfc2580">RFC 2580</a>,
               April 1999.





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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-43" ></span>
<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


   [<a id="ref-RFC3418">RFC3418</a>]   Presuhn, R., "Management Information Base (MIB) for the
               Simple Network Management Protocol (SNMP)", STD 62, <a href="./rfc3418">RFC</a>
               <a href="./rfc3418">3418</a>, December 2002.

   [<a id="ref-RFC2863">RFC2863</a>]   McCloghrie, K. and F. Kastenholz, "The Interfaces Group
               MIB", <a href="./rfc2863">RFC 2863</a>, June 2000.

   [<a id="ref-IEEE8021D">IEEE8021D</a>] IEEE Project 802 Local and Metropolitan Area Networks,
               "ANSI/IEEE Standard 802.1D-1998 MAC Bridges", March 1998.

<span class="h3"><a class="selflink" id="section-10.2" href="#section-10.2">10.2</a>  Informative References</span>

   [<a id="ref-RFC3410">RFC3410</a>]   Case, J., Mundy, R., Partain, D., and B. Stewart,
               "Introduction and Applicability Statements for Internet-
               Standard Management Framework", <a href="./rfc3410">RFC 3410</a>, December 2002.

   [<a id="ref-RFC1493">RFC1493</a>]   Decker, E., Langille, P., Rijsinghani, A., and K.
               McCloghrie, "Definitions of Managed Objects for Bridges",
               <a href="./rfc1493">RFC 1493</a>, July 1993.

   [<a id="ref-RFC1525">RFC1525</a>]   Decker, E., McCloghrie, K., Langille, P., and A.
               Rijsinghani, "Definitions of Managed Objects for Source
               Routing Bridges", <a href="./rfc1525">RFC 1525</a>, September 1993.

Authors' Addresses

   Kenyon C. Norseth (editor)
   L-3 Communications
   640 N. 2200 West
   Salt Lake City, Utah 84116-0850
   USA

   Phone: +1 801-594-2809
   EMail: kenyon.c.norseth@L-3com.com


   E. Bell (editor)
   3Com Europe Limited
   3Com Centre, Boundary Way
   Hemel Hempstead Herts.  HP2 7YU
   UK

   Phone: +44 1442 438025
   EMail: elbell@ntlworld.com







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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-44" ></span>
<span class="grey"><a href="./rfc4188">RFC 4188</a>                       Bridge MIB                 September 2005</span>


Full Copyright Statement

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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
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Norseth &amp; Bell, Eds.        Standards Track                    [Page 44]
</pre>