Network Working Group                                          E. Decker
Request for Comments: 1286                           cisco Systems, Inc.
                                                             P. Langille
                                           Digital Equipment Corporation
                                                          A. Rijsinghani
                                           Digital Equipment Corporation
                                                           K. McCloghrie
                                                Hughes LAN Systems, Inc.
                                                           December 1991
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Definitions of Managed Objects for Bridges

Status of this Memo

This memo is an extension to the SNMP MIB. This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Table of Contents

1. Abstract
2. The Network Management Framework
3. Objects
3.1 Format of Definitions
4. Overview
4.1 Structure of MIB
4.1.1 The dot1dBase Group
4.1.2 The dot1dStp Group
4.1.3 The dot1dSr Group
4.1.4 The dot1dTp Group
4.1.5 The dot1dStatic Group
4.2 Relationship to Other MIBs
4.2.1 Relationship to the 'system' group
4.2.2 Relationship to the 'interfaces' group
4.3 Textual Conventions
5. Definitions
5.1 Groups in the Bridge MIB
5.2 The dot1dBase Group Definitions
5.3 The dot1dStp Group Definitions
5.4 The dot1dSr Group Definitions
5.5 The dot1dTp Group Definitions
5.6 The dot1dStatic Group Definitions
5.8 Traps for use by Bridges
6. Acknowledgments


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7. References
8. Security Considerations
9. Authors' Addresses

1. 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 bridges based on the IEEE 802.1d draft standard between Local Area Network (LAN) segments. Provisions are made for support of transparent and source route bridging. Provisions are also made so that these objects apply to bridges connected by subnetworks other than LAN segments.

2. The Network Management Framework

The Internet-standard Network Management Framework consists of three components. They are:

RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI.

RFC 1156 which defines MIB-I, the core set of managed objects for the Internet suite of protocols. RFC 1213, defines MIB-II, an evolution of MIB-I based on implementation experience and new operational requirements.

RFC 1157 which defines the SNMP, the protocol used for network access to managed objects.

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

3. Objects

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) [7] defined in the SMI. In particular, each object has a name, a syntax, and an encoding. The name is an object identifier, an
administratively assigned name, which specifies an object type. 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 OBJECT DESCRIPTOR, to also refer to the object type.


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The syntax of an object type defines the abstract data structure corresponding to that object type. The ASN.1 language is used for this purpose. However, the SMI [3] purposely restricts the ASN.1 constructs which may be used. These restrictions are explicitly made for simplicity.

The encoding of an object type is simply how that object type is represented using the object type's syntax. Implicitly tied to the notion of an object type's syntax and encoding is how the object type is represented when being transmitted on the network.

The SMI specifies the use of the basic encoding rules of ASN.1 [8], subject to the additional requirements imposed by the SNMP.

3.1. Format of Definitions

Section 5 contains the specification of all object types contained in this MIB module. The object types are defined using the conventions defined in the SMI, as amended by the extensions specified in [9,10].

4. Overview

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 draft IEEE 802.1d specification [11]. Source route bridging has been defined by I.B.M. and is described in the Token Ring Architecture Reference [12]. IEEE 802.1d is currently working on combining the source route and transparent techniques in a compatible fashion. This memo defines those objects needed for the management of a bridging entity operating in one of these modes.

To be consistent with IAB directives and good engineering practice, an explicit attempt was made to keep this MIB 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 objects be essential for either fault or
configuration management.

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

(4) Limit the total of objects.


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(5) Exclude objects which are simply derivable from others in this or other MIBs.

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

4.1. Structure of MIB

Objects in this MIB are arranged into groups. Each group is organized as a set of related objects. The overall structure and assignment of objects to their groups is shown below. Where appropriate the corresponding IEEE 802.1d [11] management object name is also included.

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


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      State                         .SpanningTreeState
      Enable
      PathCost                      .PortPathCost
      DesignatedRoot                .DesignatedRoot
      DesignatedCost                .DesignatedCost
      DesignatedBridge              .DesignatedBridge
      DesignatedPort                .DesignatedPort
      ForwardTransitions

dot1dSr
PortTable
Port

      HopCount                    SourceRoutingPort
                                    .PortHopCount
      LocalSegment                  .SegmentNumber
      BridgeNum                     .BridgeNumber
      TargetSegment
      LargestFrame                  .LargestFrameSize
      STESpanMode                   .LimitedBroadcastMode
      SpecInFrames                BridgePort
                                    .ValidSRFramesReceived
      SpecOutFrames                 .ValidSRForwardedOutbound
      ApeInFrames
      ApeOutFrames                  .BroadcastFramesForwarded
      SteInFrames
      SteOutFrames                  .BroadcastFramesForwarded
      SegmentMismatchDiscards       .DiscardInvalidRI
      DuplicateSegmentDiscards      .LanIdMismatch
      HopCountExceededDiscards      .FramesDiscardedHopCountExceeded
  dot1dTp
    LearnedEntryDiscards          BridgeFilter.DatabaseSize
                                    .NumDynamic,NumStatic
    AgingTime                     BridgeFilter.AgingTime
    FdbTable
      Address
      Status
      Port
    PortTable
      Port
      MaxInfo
      InFrames                    BridgePort.FramesReceived
      OutFrames                     .ForwardOutbound
      InDiscards                    .DiscardInbound
  dot1dStatic
    StaticTable
      Address
      ReceivePort
      AllowedToGoTo


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Status

The following IEEE 802.1d management objects have not been included in the Bridge MIB for the indicated reasons.

IEEE 802.1d Object Disposition

Bridge.BridgeName Same as sysDescr (MIB II)
Bridge.BridgeUpTime Same as sysUpTime (MIB II)
Bridge.PortAddresses Same as ifPhysAddress (MIB II)
BridgePort.PortName Same as ifDescr (MIB II)
BridgePort.PortType Same as ifType (MIB II)
BridgePort.RoutingType Derivable from the implemented
groups

SpanningTreeProtocol
    .BridgeIdentifier           Combination of dot1dStpPriority
                                and dot1dBaseBridgeAddress
    .TopologyChange             Since this is transitory, it
                                is not considered useful.
SpanningTreeProtocolPort
    .Uptime                     Same as ifLastChange (MIB II)
    .PortIdentifier             Combination of dot1dStpPortNum
                                and dot1dStpPortPriority
    .TopologyChangeAcknowledged Since this is transitory, it
                                is not considered useful.
    .DiscardLackOfBuffers       Redundant

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

SourceRoutingPort The Source Routing Supplement,
at the time of this writing, is not stable. The following objects were NOT included in this MIB because they are
redundant or not considered
useful.
.LimitedBroadcastEnable
BridgePort.DupLanIdOrTreeError
.DiscardLackOfBuffers
.DiscardErrorDetails
.DiscardTargetLANInoperable


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.ValidSRDiscardedInbound
.BroadcastBytesForwarded
.NonBroadcastBytesForwarded
.FramesNotReceivedDueToCongestion
.FramesDiscardedDueToInternalError

4.1.1. The dot1dBase Group

This mandatory group contains the objects which are applicable to all types of bridges.

4.1.2. The dot1dStp Group

This group contains the objects that denote the bridge's state with respect to the Spanning Tree Protocol. If a node does not implemented the Spanning Tree Protocol, this group will not be implemented. This group is applicable to any transparent only, source route, or SRT bridge which implements the Spanning Tree Protocol.

4.1.3. The dot1dSr Group

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

4.1.4. The dot1dTp Group

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

4.1.5. The dot1dStatic Group

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

4.2. Relationship to Other MIBs

As described above, some IEEE 802.1d management objects have not been included in this MIB because they overlap with objects in other MIBs applicable to a bridge implementing this MIB. In particular, it is assumed that a bridge implementing this MIB will also implement (at


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least) the 'system' group and the 'interfaces' group defined in MIB- II [6].

4.2.1. Relationship to the 'system' group

In MIB-II, the 'system' group is defined as being mandatory for all systems such that each managed entity contains one instance of each object in the 'system' group. Thus, those objects apply to the entity as a whole irrespective of whether the entity's sole functionality is bridging, or whether bridging is only a subset of the entity's functionality.

4.2.2. Relationship to the 'interfaces' group

In MIB-II, the 'interfaces' group is defined as being mandatory for all systems and contains information on an entity's interfaces, where each 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.

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' group, 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 but 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).

Some entities perform other functionality 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 which exclusively performed bridging, all protocols would be considered as being bridged, whereas in an entity which performed IP routing on IP datagrams and only bridged other protocols, only the non-IP data would be considered as being bridged.


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

4.3. Textual Conventions

The datatypes, MacAddress, BridgeId and Timeout, are used as textual conventions in this document. These textual conventions have NO effect on either the syntax nor the semantics of any managed object. Objects defined using these conventions are always encoded by means of the rules that define their primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate these textual conventions which are adopted merely for the convenience of readers.

5. Definitions

   RFC1286-MIB DEFINITIONS ::= BEGIN

IMPORTS
Counter, Gauge, TimeTicks
FROM RFC1155-SMI
mib-2
FROM RFC1213-MIB
OBJECT-TYPE
FROM RFC-1212
TRAP-TYPE
FROM RFC-1215;

   -- All representations of MAC addresses in this MIB Module use,
   -- as a textual convention (i.e. this convention does not affect
   -- their encoding), the data type:

   MacAddress ::= OCTET STRING (SIZE (6))    -- a 6 octet address in
                                             -- the "canonical" order
   -- defined by IEEE 802.1a, i.e., as if it were transmitted least
   -- significant bit first, even though 802.5 (in contrast to other
   -- 802.x protocols) requires MAC addresses to be transmitted most
   -- significant bit first.
   --
   -- 16-bit addresses, if needed, are represented by setting their
   -- upper 4 octets to all 0's, i.e., AAFF would be represented
   -- as 00000000AAFF.

   -- Similarly, all representations of Bridge-Id in this MIB Module
   -- use, as a textual convention (i.e. this convention does not affect
   -- their encoding), the data type:


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   BridgeId ::= OCTET STRING (SIZE (8))   -- 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).
   -- 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 hundreths 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/D9
   -- specifies a settable granularity of no more than 1 second for
   -- these timers.  To avoid ambiguity, a data type is defined here
   -- as a textual convention and all representation of these timers
   -- in this MIB module are defined using this data type.  An algorithm
   -- is also defined for converting between the different units, to
   -- ensure a timer's value is not distorted by multiple conversions.
   -- The data type is:

   Timeout ::= INTEGER      -- a STP timer in units of 1/100 seconds

   -- 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 non-zero]
   --      n is the value in 1/100 second units
   --      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).

   dot1dBridge   OBJECT IDENTIFIER ::= { mib-2 17 }


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   -- groups in the Bridge MIB

   dot1dBase     OBJECT IDENTIFIER ::= { dot1dBridge 1 }

   dot1dStp      OBJECT IDENTIFIER ::= { dot1dBridge 2 }

   dot1dSr       OBJECT IDENTIFIER ::= { dot1dBridge 3 }

   dot1dTp       OBJECT IDENTIFIER ::= { dot1dBridge 4 }

   dot1dStatic   OBJECT IDENTIFIER ::= { dot1dBridge 5 }

   -- the dot1dBase group

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

dot1dBaseBridgeAddress OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-only
STATUS mandatory
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 required to be unique. When concatenated with dot1dStpPriority a unique BridgeIdentifier is formed which is used in the Spanning Tree Protocol."
REFERENCE
"P802.1d/D9, July 14, 1989: Sections 6.4.1.1.3 and 3.12.5"

       ::= { dot1dBase 1 }

dot1dBaseNumPorts OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of ports controlled by this bridging entity."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.4.1.1.3"

       ::= { dot1dBase 2 }

dot1dBaseType OBJECT-TYPE
SYNTAX INTEGER {


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unknown(1),
transparent-only(2),
sourceroute-only(3),
srt(4)
}
ACCESS read-only
STATUS mandatory
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
ACCESS not-accessible
STATUS mandatory
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 }

dot1dBasePortEntry OBJECT-TYPE
SYNTAX Dot1dBasePortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of information for each port of the
bridge."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.4.2, 6.6.1" INDEX { dot1dBasePort }

       ::= { dot1dBasePortTable 1 }

   Dot1dBasePortEntry ::=
       SEQUENCE {
           dot1dBasePort
               INTEGER,
           dot1dBasePortIfIndex
               INTEGER,
           dot1dBasePortCircuit
               OBJECT IDENTIFIER,
           dot1dBasePortDelayExceededDiscards


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Counter,
dot1dBasePortMtuExceededDiscards
Counter
}

dot1dBasePort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port number of the port for which this entry contains bridge management information."

       ::= { dot1dBasePortEntry 1 }

dot1dBasePortIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The value of the instance of the ifIndex object, defined in [4,6], for the interface corresponding to this port."

       ::= { dot1dBasePortEntry 2 }

dot1dBasePortCircuit OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"For a port which (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 Counter
ACCESS read-only
STATUS mandatory


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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
"P802.1d/D9, July 14, 1989: Section 6.6.1.1.3"

       ::= { dot1dBasePortEntry 4 }

dot1dBasePortMtuExceededDiscards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 6.6.1.1.3"

       ::= { dot1dBasePortEntry 5 }

   -- the dot1dStp group

   -- Implementation of the dot1dStp group is optional.  It is
   -- implemented by those bridges that support the Spanning Tree
   -- Protocol.  Transparent, Source Route, and SRT bridges will
   -- implement this group only if they support the Spanning Tree
   -- Protocol.

dot1dStpProtocolSpecification OBJECT-TYPE
SYNTAX INTEGER {
unknown(1),
decLb100(2),
ieee8021d(3)
}
ACCESS read-only
STATUS mandatory
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 are released that are incompatible with the
current version a new value will be defined."


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       ::= { dot1dStp 1 }

dot1dStpPriority OBJECT-TYPE
SYNTAX INTEGER (0..65535)
ACCESS read-write
STATUS mandatory
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."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.7"

       ::= { dot1dStp 2 }

dot1dStpTimeSinceTopologyChange OBJECT-TYPE
SYNTAX TimeTicks
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The time (in hundredths of a second) since the last time a topology change was detected by the bridge entity."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.8.1.1.3"

       ::= { dot1dStp 3 }

dot1dStpTopChanges OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of topology changes detected by this bridge since the management entity was last reset or initialized."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.8.1.1.3"

       ::= { dot1dStp 4 }

dot1dStpDesignatedRoot OBJECT-TYPE
SYNTAX BridgeId
ACCESS read-only
STATUS mandatory
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


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the Root Identifier parameter in all Configuration Bridge PDUs originated by this node."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.1"

       ::= { dot1dStp 5 }

dot1dStpRootCost OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The cost of the path to the root as seen from this bridge."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.2"

       ::= { dot1dStp 6 }

dot1dStpRootPort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port number of the port which offers the lowest cost path from this bridge to the root bridge."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.3"

       ::= { dot1dStp 7 }

dot1dStpMaxAge OBJECT-TYPE
SYNTAX Timeout
ACCESS read-only
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 4.5.3.4"

       ::= { dot1dStp 8 }

dot1dStpHelloTime OBJECT-TYPE
SYNTAX Timeout
ACCESS read-only
STATUS mandatory
DESCRIPTION


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"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
"P802.1d/D9, July 14, 1989: Section 4.5.3.5"

       ::= { dot1dStp 9 }

dot1dStpHoldTime OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 4.5.3.14"

       ::= { dot1dStp 10 }

dot1dStpForwardDelay OBJECT-TYPE
SYNTAX Timeout
ACCESS read-only
STATUS mandatory
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 a particular state before moving to the next state. For example, how long a port stays in the Listening state when moving from Blocking to Learning. 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
"P802.1d/D9, July 14, 1989: Section 4.5.3.6"

       ::= { dot1dStp 11 }


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dot1dStpBridgeMaxAge OBJECT-TYPE
SYNTAX Timeout (600..4000)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value that all bridges use for MaxAge when this bridge is acting as the root. Note that 802.1d/D9 specifies that the range for this
parameter is related to the value of
dot1dStpBridgeHelloTime. The granularity of this timer is specified by 802.1d/D9 to be 1 second. An agent may return a badValue error if a set is attempted to a value which is not a whole number of seconds."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.8"

       ::= { dot1dStp 12 }

dot1dStpBridgeHelloTime OBJECT-TYPE
SYNTAX Timeout (100..1000)
ACCESS read-write
STATUS mandatory
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/D9 to be 1 second. An agent may return a
badValue error if a set is attempted to a value which is not a whole number of seconds."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.3.9"
       ::= { dot1dStp 13 }

dot1dStpBridgeForwardDelay OBJECT-TYPE
SYNTAX Timeout (400..3000)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value that all bridges use for ForwardDelay when this bridge is acting as the root. Note that 802.1d/D9 specifies that the range for this
parameter is related to the value of
dot1dStpBridgeMaxAge. The granularity of this timer is specified by 802.1d/D9 to be 1 second. An agent may return a badValue error if a set is attempted to a value which is not a whole number of seconds."
REFERENCE


Page 19

"P802.1d/D9, July 14, 1989: Section 4.5.3.10"

       ::= { dot1dStp 14 }

   -- The Spanning Tree Port Table

dot1dStpPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot1dStpPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table that contains port-specific information for the Spanning Tree Protocol."

       ::= { dot1dStp 15 }

dot1dStpPortEntry OBJECT-TYPE
SYNTAX Dot1dStpPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of information maintained by every port about the Spanning Tree Protocol state for that port."

       INDEX   { dot1dStpPort }
       ::= { dot1dStpPortTable 1 }

   Dot1dStpPortEntry ::=
       SEQUENCE {
           dot1dStpPort
               INTEGER,
           dot1dStpPortPriority
               INTEGER,
           dot1dStpPortState
               INTEGER,
           dot1dStpPortEnable
               INTEGER,
           dot1dStpPortPathCost
               INTEGER,
           dot1dStpPortDesignatedRoot
               BridgeId,
           dot1dStpPortDesignatedCost
               INTEGER,
           dot1dStpPortDesignatedBridge
               BridgeId,
           dot1dStpPortDesignatedPort
               OCTET STRING,
           dot1dStpPortForwardTransitions
               Counter


Page 20

}

dot1dStpPort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port number of the port for which this entry contains Spanning Tree Protocol management
information."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.8.2.1.2"

       ::= { dot1dStpPortEntry 1 }

dot1dStpPortPriority OBJECT-TYPE
SYNTAX INTEGER (0..255)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The value of the priority field which 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."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.1"

       ::= { dot1dStpPortEntry 2 }

dot1dStpPortState OBJECT-TYPE
SYNTAX INTEGER {
disabled(1),
blocking(2),
listening(3),
learning(4),
forwarding(5),
broken(6)
}
ACCESS read-only
STATUS mandatory
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 which are disabled (see dot1dStpPortEnable), this object will have a value of disabled(1)."


Page 21

REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.2"

       ::= { dot1dStpPortEntry 3 }

dot1dStpPortEnable OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The enabled/disabled status of the port."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.2"

       ::= { dot1dStpPortEntry 4 }

dot1dStpPortPathCost OBJECT-TYPE
SYNTAX INTEGER (1..65535)
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The contribution of this port to the path cost of paths towards the spanning tree root which include this port."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.3"

       ::= { dot1dStpPortEntry 5 }

dot1dStpPortDesignatedRoot OBJECT-TYPE
SYNTAX BridgeId
ACCESS read-only
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 4.5.5.4"

       ::= { dot1dStpPortEntry 6 }

dot1dStpPortDesignatedCost OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The path cost of the Designated Port of the


Page 22

segment connected to this port. This value is compared to the Root Path Cost field in received bridge PDUs."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.5"

       ::= { dot1dStpPortEntry 7 }

dot1dStpPortDesignatedBridge OBJECT-TYPE
SYNTAX BridgeId
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The Bridge Identifier of the bridge which this port considers to be the Designated Bridge for this port's segment."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.6"

       ::= { dot1dStpPortEntry 8 }

dot1dStpPortDesignatedPort OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (2))
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The Port Identifier of the port on the Designated Bridge for this port's segment."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 4.5.5.7"

       ::= { dot1dStpPortEntry 9 }

dot1dStpPortForwardTransitions OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of times this port has transitioned from the Learning state to the Forwarding state."

       ::= { dot1dStpPortEntry 10 }

   -- the dot1dSr group

   -- Implementation of the dot1dSr group is optional.  It is
   -- implemented by those bridges that support the source route
   -- bridging mode, including Source Route and SRT bridges.


Page 23

dot1dSrPortTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot1dSrPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table that contains information about every port that is associated with this source route bridge."

       ::= { dot1dSr 1 }

dot1dSrPortEntry OBJECT-TYPE
SYNTAX Dot1dSrPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of information for each port of a source route bridge."

       INDEX   { dot1dSrPort }
       ::= { dot1dSrPortTable 1 }

   Dot1dSrPortEntry ::=
       SEQUENCE {
           dot1dSrPort
               INTEGER,
           dot1dSrPortHopCount
               INTEGER,
           dot1dSrPortLocalSegment
               INTEGER,
           dot1dSrPortBridgeNum
               INTEGER,
           dot1dSrPortTargetSegment
               INTEGER,
           dot1dSrPortLargestFrame
               INTEGER,
           dot1dSrPortSTESpanMode
               INTEGER,
           dot1dSrPortSpecInFrames
               Counter,
           dot1dSrPortSpecOutFrames
               Counter,
           dot1dSrPortApeInFrames
               Counter,
           dot1dSrPortApeOutFrames
               Counter,
           dot1dSrPortSteInFrames
               Counter,
           dot1dSrPortSteOutFrames
               Counter,


Page 24

dot1dSrPortSegmentMismatchDiscards
Counter,
dot1dSrPortDuplicateSegmentDiscards
Counter,
dot1dSrPortHopCountExceededDiscards
Counter
}

dot1dSrPort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The port number of the port for which this entry contains Source Route management information."

       ::= { dot1dSrPortEntry 1 }

dot1dSrPortHopCount OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The maximum number of routing descriptors allowed in an All Paths or Spanning Tree Explorer frames."

       ::= { dot1dSrPortEntry 2 }

dot1dSrPortLocalSegment OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The segment number that uniquely identifies the segment to which this port is connected. Current source routing protocols limit this value to the range: 0 through 4095. A value of 65535 signifies that no segment number is assigned to this port."

       ::= { dot1dSrPortEntry 3 }

dot1dSrPortBridgeNum OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"A bridge number uniquely identifies a bridge when more than one bridge is used to span the same two segments. Current source routing protocols limit this value to the range: 0 through 15. A value of 65535 signifies that no bridge number is assigned


Page 25

to this bridge."

       ::= { dot1dSrPortEntry 4 }

dot1dSrPortTargetSegment OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The segment number that corresponds to the target segment this port is considered to be connected to by the bridge. Current source routing protocols limit this value to the range: 0 through 4095. A value of 65535 signifies that no target segment is assigned to this port."

       ::= { dot1dSrPortEntry 5 }

   -- It would be nice if we could use ifMtu as the size of the
   -- largest frame, 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).

dot1dSrPortLargestFrame OBJECT-TYPE
SYNTAX INTEGER {

                   dot1dSrMtu516   (516),
                   dot1dSrMtu1500  (1500),
                   dot1dSrMtu2052  (2052),
                   dot1dSrMtu4472  (4472),
                   dot1dSrMtu8144  (8144),
                   dot1dSrMtu11407 (11407), -- yes this is correct don't
                   dot1dSrMtu17800 (17800), -- ask me where it came from.
                   dot1dSrMtu65535 (65535)
               }

ACCESS read-write
STATUS mandatory
DESCRIPTION
"The maximum size of the INFO field (LLC and
above) that this port can send/receive. It does not include any MAC level (framing) octets. The value of this object is used by this bridge to determine whether a modification of the
LargestFrame (LF, see [14]) field of the Routing Control field of the Routing Information Field is necessary. Valid values as defined by the 802.5 source routing bridging specification[14] are 516, 1500, 2052, 4472, 8144, 11407, 17800, and 65535 octets. Behavior of the port when an illegal


Page 26

value is written is implementation specific. It is recommended that a reasonable legal value be chosen."

       ::= { dot1dSrPortEntry 6 }

dot1dSrPortSTESpanMode OBJECT-TYPE
SYNTAX INTEGER {
auto-span(1),
disabled(2),
forced(3)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"Determines how this port behaves when presented with a Spanning Tree Explorer frame. The value 'disabled(2)' indicates that the port will not accept or send Spanning Tree Explorer packets; any STE packets received will be silently discarded. The value 'forced(3)' indicates the port will always accept and propagate Spanning Tree Explorer frames. This allows a manually configured
Spanning Tree for this class of packet to be
configured. Note that unlike transparent bridging this is not catastrophic to the network if there are loops. The value 'auto-span(1)' can only be returned by a bridge that both implements the Spanning Tree Protocol and has use of the protocol enabled on this port. The behavior of the port for Spanning Tree Explorer frames is determined by the state of dot1dStpPortState. If the port is in the 'forwarding' state, the frame will be accepted or propagated. Otherwise it will be silently
discarded."

       ::= { dot1dSrPortEntry 7 }

dot1dSrPortSpecInFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of specifically routed frames that have been received from this port's segment."

       ::= { dot1dSrPortEntry 8 }

dot1dSrPortSpecOutFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only


Page 27

STATUS mandatory
DESCRIPTION
"The number of specifically routed frames that this port has transmitted on its segment."

       ::= { dot1dSrPortEntry 9 }

dot1dSrPortApeInFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of all paths explorer frames that have been received by this port from its segment."

       ::= { dot1dSrPortEntry 10 }

dot1dSrPortApeOutFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of all paths explorer frames that have been transmitted by this port on its segment."

       ::= { dot1dSrPortEntry 11 }

dot1dSrPortSteInFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of spanning tree explorer frames that have been received by this port from its segment."

       ::= { dot1dSrPortEntry 12 }

dot1dSrPortSteOutFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of spanning tree explorer frames that have been transmitted by this port on its
segment."

       ::= { dot1dSrPortEntry 13 }

dot1dSrPortSegmentMismatchDiscards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION


Page 28

"The number of explorer frames that have been discarded by this port because the routing
descriptor field contained an invalid adjacent segment value."

       ::= { dot1dSrPortEntry 14 }

dot1dSrPortDuplicateSegmentDiscards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of frames that have been discarded by this port because the routing descriptor field contained a duplicate segment identifier."

       ::= { dot1dSrPortEntry 15 }

dot1dSrPortHopCountExceededDiscards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The number of explorer frames that have been discarded by this port because the Routing
Information Field has exceeded the maximum route descriptor length."

       ::= { dot1dSrPortEntry 16 }

   -- the dot1dTp group

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

dot1dTpLearnedEntryDiscards OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
DESCRIPTION
"The total number of Forwarding Database entries, which have been or would have been learnt, but have been discarded due to a lack of space to store them in the Forwarding Database. If this counter is increasing, it indicates that the
Forwarding Database is regularly becoming full (a condition which has unpleasant performance effects


Page 29

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
"P802.1d/D9, July 14, 1989: Section 6.7.1.1.3"

       ::= { dot1dTp 1 }

dot1dTpAgingTime OBJECT-TYPE

       SYNTAX   INTEGER
       ACCESS   read-write
       STATUS   mandatory
       DESCRIPTION
               "The timeout period in seconds for aging out
               dynamically learned forwarding information."
       REFERENCE
               "P802.1d/D9, July 14, 1989: Section 6.7.1.1.3"
       ::= { dot1dTp 2 }

   --  The Forwarding Database for Transparent Bridges

dot1dTpFdbTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot1dTpFdbEntry
ACCESS not-accessible
STATUS mandatory
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
SYNTAX Dot1dTpFdbEntry
ACCESS not-accessible
STATUS mandatory
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


Page 30

MacAddress,
dot1dTpFdbPort
INTEGER,
dot1dTpFdbStatus
INTEGER
}

dot1dTpFdbAddress OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A unicast MAC address for which the bridge has forwarding and/or filtering information."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 3.9.1, 3.9.2"

       ::= { dot1dTpFdbEntry 1 }

dot1dTpFdbPort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
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 }

dot1dTpFdbStatus OBJECT-TYPE
SYNTAX INTEGER {
other(1),
invalid(2),
learned(3),
self(4),
mgmt(5)
}
ACCESS read-only
STATUS mandatory


Page 31

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 not 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
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A table that contains information about every port that is associated with this transparent


Page 32

bridge."

       ::= { dot1dTp 4 }

dot1dTpPortEntry OBJECT-TYPE
SYNTAX Dot1dTpPortEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"A list of information for each port of a
transparent bridge."

       INDEX   { dot1dTpPort }
       ::= { dot1dTpPortTable 1 }

   Dot1dTpPortEntry ::=
       SEQUENCE {
           dot1dTpPort
               INTEGER,
           dot1dTpPortMaxInfo
               INTEGER,
           dot1dTpPortInFrames
               Counter,
           dot1dTpPortOutFrames
               Counter,
           dot1dTpPortInDiscards
               Counter
       }

dot1dTpPort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-only
STATUS mandatory
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 INTEGER
ACCESS read-only
STATUS mandatory
DESCRIPTION


Page 33

"The maximum size of the INFO (non-MAC) field that this port will receive or transmit."

       ::= { dot1dTpPortEntry 2 }

dot1dTpPortInFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
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."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.6.1.1.3"

       ::= { dot1dTpPortEntry 3 }

dot1dTpPortOutFrames OBJECT-TYPE
SYNTAX Counter
ACCESS read-only
STATUS mandatory
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."
REFERENCE
"P802.1d/D9, July 14, 1989: Section 6.6.1.1.3"

       ::= { dot1dTpPortEntry 4 }

dot1dTpPortInDiscards OBJECT-TYPE

       SYNTAX   Counter
       ACCESS   read-only
       STATUS   mandatory
       DESCRIPTION
               "Count of valid frames received which were
               discarded (i.e., filtered) by the Forwarding
               Process."
       REFERENCE
               "P802.1d/D9, July 14, 1989: Section 6.6.1.1.3"
       ::= { dot1dTpPortEntry 5 }


Page 34

   -- The Static (Destination-Address Filtering) Database

   -- Implementation of this group is optional.

dot1dStaticTable OBJECT-TYPE
SYNTAX SEQUENCE OF Dot1dStaticEntry
ACCESS not-accessible
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 6.7.2"

       ::= { dot1dStatic 1 }

dot1dStaticEntry OBJECT-TYPE
SYNTAX Dot1dStaticEntry
ACCESS not-accessible
STATUS mandatory
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
"P802.1d/D9, July 14,1989: Section 6.7.2"

       INDEX   { dot1dStaticAddress, dot1dStaticReceivePort }
       ::= { dot1dStaticTable 1 }

   Dot1dStaticEntry ::=
       SEQUENCE {
           dot1dStaticAddress
               MacAddress,
           dot1dStaticReceivePort
               INTEGER,
           dot1dStaticAllowedToGoTo


Page 35

OCTET STRING,
dot1dStaticStatus
INTEGER
}

dot1dStaticAddress OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-write
STATUS mandatory
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
"P802.1d/D9, July 14, 1989: Section 3.9.1, 3.9.2"

       ::= { dot1dStaticEntry 1 }

dot1dStaticReceivePort OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
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
ACCESS read-write
STATUS mandatory
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


Page 36

'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.)"

       ::= { dot1dStaticEntry 3 }

dot1dStaticStatus OBJECT-TYPE
SYNTAX INTEGER {
other(1),
invalid(2),
permanent(3),
deleteOnReset(4),
deleteOnTimeout(5)
}
ACCESS read-write
STATUS mandatory
DESCRIPTION
"This object indicates the status of this entry. 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 }

   -- Traps for use by Bridges

   -- Traps for the Spanning Tree Protocol

newRoot TRAP-TYPE
ENTERPRISE dot1dBridge
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 root, e.g., upon expiration of the Topology Change Timer immediately subsequent to


Page 37

its election."

       ::= 1

topologyChange TRAP-TYPE
ENTERPRISE dot1dBridge
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."

       ::= 2

END

6. Acknowledgments

This document was produced on behalf of the Bridge Sub-Working Group of the SNMP Working Group of the Internet Engineering Task Force. Over the course of its deliberations, the working group received four separate documents for consideration as the basis for its work. The first was submitted by Stan Froyd of Advanced Computer
Communications; the second by Richard Fox of SynOptics; the third by Eric Decker of cisco Inc. and Keith McCloghrie of Hughes LAN Systems; and the fourth by Paul Langille and Anil Rijsinghani of Digital Equipment Corp. After considering the submissions, the working group chose to proceed with a document formed as a conjunction of the latter two submissions. This document is the result.

The authors wish to thank the members of the Bridge Working Group for their many comments and suggestions which improved this effort. In particular, Fred Baker (chairman of the working group) of ACC, Steve Sherry of Xyplex, and Frank Kastenholz of Clearpoint Research Corp. Others members of the Bridge Working Group who contributed to this effort are:

Bill Anderson, Mitre
Karl Auerbach, Epilogue
Fred Baker, ACC (chair)
Terry Bradley, Wellfleet
Ted Brunner, Bellcore
Jeffrey Buffum, Apollo
Chris ChioTasso, Fibronics
Anthony Chung, HLS
Chuck Davin, MIT-LCS
Andy Davis, Spider
Eric Decker, cisco


Page 38

Nadya El-Afandi, Network Systems
Gary Ellis,HP/Apollo
Richard Fox, SynOptics
Stan Froyd, ACC
Frank Kastenholz, Clearpoint Research
Shirnshon Kaufman,
Jim Kinder, Fibercom
Cheryl Krupczak,NCR
Paul Langille, Digital
Peter Lin,Vitalink
Keith McCloghrie, HLS
Donna McMaster, SynOptics
Dave Perkins, 3Com
Jim Reinstedler, Ungermann Bass
Anil Rijsinghani, Digital
Mark Schaefer, David Systems
Steve Sherry, Xyplex
Bob Stewart, Xyplex
Emil Sturniolo,
Kevin Synott, Retix
Ian Thomas, Chipcom
Maurice Turcott, Racal
Fei Xu,

7. References

[1] Cerf, V., "IAB Recommendations for the Development of Internet Network Management Standards", RFC 1052, NRI, April 1988.

[2] Cerf, V., "Report of the Second Ad Hoc Network Management Review Group", RFC 1109, NRI, August 1989.

[3] Rose M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based internets", RFC 1155, Performance Systems International, Hughes LAN Systems, May 1990.

[4] McCloghrie K., and M. Rose, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1156, Hughes LAN Systems, Performance Systems International, May 1990.

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

[6] McCloghrie K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1213, Performance Systems International, March 1991.


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[7] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization, International Standard 8824, December 1987.

[8] Information processing systems - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Notation One (ASN.1), International Organization for Standardization, International Standard 8825, December 1987.

[9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions", RFC 1212, Performance Systems International, Hughes LAN Systems, March 1991.

[10] Rose, M., Editor, "A Convention for Defining Traps for use with the SNMP", RFC 1215, Performance Systems International, March 1991.

[11] ANSI/IEEE Draft P802.1d/D9 MAC Bridges, "IEEE Project 802 Local and Metropolitan Area Networks", July 14, 1989.

[12] I.B.M. Token Ring Architecture Reference.

[13] ISO DIS 10038 MAC Bridges.

[14] ANSI/IEEE P802.1x/P802.5x, "Proposed Draft Local Area Network Standard -- MAC Bridges, Source Routing Supplement", IEEE Project 802, September 1990.

[15] ANSI/IEEE 802.1y, "Source Routing Tutorial for End System Operation", September 1990.

8. Security Considerations

Security issues are not discussed in this memo.


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9. Authors' Addresses

Eric B. Decker
cisco Systems, Inc.
1525 O'Brien Dr.
Menlo Park, CA 94025

Phone: (415) 326-1941
Email: cire@cisco.com

Paul Langille
Digital Equipment Corporation
Digital Drive, MK02-2/K03
Merrimack, NH 03054

Phone: (603) 884-4045
EMail: langille@edwin.enet.dec.com

Anil Rijsinghani
Digital Equipment Corporation
153 Taylor St.
Littleton, MA 01460

Phone: (508)952-3520
EMail: anil@levers.enet.dec.com

Keith McCloghrie
Hughes LAN Systems
1225 Charleston Road
Mountain View, CA 94043

Phone: (415) 966-7934
EMail: kzm@hls.com