Internet DRAFT - draft-decker-bridge-sr-obj

draft-decker-bridge-sr-obj




                        Definitions of Managed Objects for
                              Source Routing Bridges


                          19 February 17:30:15 EST 1996


                        Draft Expiration Date: August 1996


                                  Eric B. Decker
                               cisco Systems, Inc.
                                  cire@cisco.com


                                 Keith McCloghrie
                               cisco Systems, Inc.
                                  kzm@cisco.com


                                  Paul Langille
                                Ascom Nexion, Inc.
                                langille@nexen.com


                                 Anil Rijsinghani
                          Digital Equipment Corporation
                             anil@netcad.enet.dec.com


                               Status of this Memo

          This document is an Internet Draft.  Internet Drafts are
          working documents of the Internet Engineering Task Force
          (IETF), its Areas, and its Working Groups.  Note that other
          groups may also distribute working documents as Internet
          Drafts.

          Internet Drafts are valid for a maximum of six months and may
          be updated, replaced, or obsoleted by other documents at any
          time.  It is inappropriate to use Internet Drafts as reference
          material or to cite them other than as a "work in progress".














          Internet Draft    Source Routing Bridge MIB           Feb 1996


          1.  Introduction

          This memo defines a portion of the Management Information Base
          (MIB) for use with network management protocols in the
          Internet community.  In particular, it defines managed objects
          used for managing source routing and source routing
          transparent bridges.  These bridges are also required to
          implement relevant groups in the Bridge MIB [4].










































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          2.  The Network Management Framework

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

          o    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.

          o    RFC 1213 defines MIB-II, the core set of managed objects
               for the Internet suite of protocols.

          o    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.


          2.1.  Object Definitions

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


















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          3.  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 IEEE 802.1d MAC Bridge
          specification [7].  Source route bridging has been defined by
          I.B.M. and is described in the Token Ring Architecture
          Reference[8], as well as the IEEE 802.5M SRT Bridge Operations
          Addendum [10] to 802.1d.  This memo defines objects needed for
          management of a source routing bridge, and is an extension to
          the SNMP Bridge MIB [4].

          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.

          (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.


          3.1.  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 management object name
          found in IEEE 802.1d[7] and IEEE 802.5M [10] is also included.

          SR Bridge MIB Name              IEEE Name





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            dot1dSr
              PortTable
                Port                        SourceRoutingPort
                HopCount
                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


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


          IEEE Object                     Disposition

          SourceRoutingPort
                                          The following objects were NOT
                                          included in this MIB because they are
                                          redundant or not considered  useful.
              .LimitedBroadcastEnable
              .DiscardLackOfBuffers
              .DiscardErrorDetails
              .DiscardTargetLANInoperable
              .ValidSRDiscardedInbound
              .BroadcastBytesForwarded
              .NonBroadcastBytesForwarded
              .FramesNotReceivedDueToCongestion
              .FramesDiscardedDueToInternalError










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          3.1.1.  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.

          3.1.2.  The dot1dPortPair Group

          Implementation of this group is optional.  This group is
          implemented by those bridges that support the port-pair
          multiport model of the source route bridging mode as defined
          in the IEEE 802.5M SRT Addendum to 802.1d.

          3.2.  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 least) the Bridge MIB and the
          'system' group and the 'interfaces' group defined in MIB-II
          [2].

          3.2.1.  Relationship to the Bridge MIB

          The Bridge MIB [4] must be implemented by all bridges,
          including transparent, SR and SRT bridges.  The SR bridge MIB
          is an extension to the Bridge MIB.


          3.2.2.  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.










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          3.2.3.  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.

          Implicit in this 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.

          Some entities provide other services in addition to bridging
          with respect to the data sent and received by 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.

          Thus, this 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.







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          4.  Changes from RFC 1525

          (1)  Removed dot1dSrPortLanIdMismatches, as it is redundant
               with dot1dSrPortSegmentMismatchDiscards.

          (2)  Replaced the words "explorer frames" in the definition of
               dot1dSrPortSegmentMismatchDiscards with the words "ARE
               and STE explorer frames" for clarification.

          (3)  Revised definition of dot1dSrPortHopCount.








































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          5.  Definitions


          SR-BRIDGE-MIB DEFINITIONS ::= BEGIN

          IMPORTS
                  Counter, Gauge
                          FROM RFC1155-SMI
                  dot1dBridge, dot1dSr
                          FROM BRIDGE-MIB
                  OBJECT-TYPE
                          FROM RFC-1212;



          -- groups in the SR MIB

          -- dot1dSr is imported from the Bridge MIB

          dot1dPortPair   OBJECT IDENTIFIER ::= { dot1dBridge 10 }
                                             -- use 10, to be safe





























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          -- the dot1dSr group

          -- this group is implemented by those bridges that
          -- support the source route bridging mode, including Source
          -- Routing and SRT bridges.


          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,





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                  dot1dSrPortSpecOutFrames
                      Counter,
                  dot1dSrPortApeInFrames
                      Counter,
                  dot1dSrPortApeOutFrames
                      Counter,
                  dot1dSrPortSteInFrames
                      Counter,
                  dot1dSrPortSteOutFrames
                      Counter,
                  dot1dSrPortSegmentMismatchDiscards
                      Counter,
                  dot1dSrPortDuplicateSegmentDiscards
                      Counter,
                  dot1dSrPortHopCountExceededDiscards
                      Counter,
                  dot1dSrPortDupLanIdOrTreeErrors
                      Counter
              }

          dot1dSrPort OBJECT-TYPE
              SYNTAX  INTEGER (1..65535)
              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 route descriptors allowed
                      in All Routes Explorer frames transmitted on this
                      port."
              ::= { dot1dSrPortEntry 2 }

          dot1dSrPortLocalSegment OBJECT-TYPE
              SYNTAX  INTEGER
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "The segment number that uniquely identifies the





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                      segment to which this port is connected. Current
                      source routing protocols limit this value to the
                      range: 0 through 4095. (The value 0 is used by
                      some management applications for special test
                      cases.) 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
                      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.
                      (The value 0 is used by some management
                      applications for special test cases.) 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
              ACCESS  read-write





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              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 [10]) field of the Routing
                      Control field of the Routing Information Field is
                      necessary.

                      64 valid values are defined by the IEEE 802.5M SRT
                      Addendum: 516, 635, 754, 873, 993, 1112, 1231,
                      1350, 1470, 1542, 1615, 1688, 1761, 1833, 1906,
                      1979, 2052, 2345, 2638, 2932, 3225, 3518, 3812,
                      4105, 4399, 4865, 5331, 5798, 6264, 6730, 7197,
                      7663, 8130, 8539, 8949, 9358, 9768, 10178, 10587,
                      10997, 11407, 12199, 12992, 13785, 14578, 15370,
                      16163, 16956, 17749, 20730, 23711, 26693, 29674,
                      32655, 35637, 38618, 41600, 44591, 47583, 50575,
                      53567, 56559, 59551, and 65535.

                      An illegal value will not be accepted by the
                      bridge."
              ::= { 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





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                      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, also
                      referred to as Source Routed Frames, that have
                      been received from this port's segment."
              ::= { dot1dSrPortEntry 8 }

          dot1dSrPortSpecOutFrames OBJECT-TYPE
              SYNTAX  Counter
              ACCESS  read-only
              STATUS  mandatory
              DESCRIPTION
                      "The number of Specifically Routed frames, also
                      referred to as Source 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, also
                      referred to as All Routes Explorer frames, that
                      have been received by this port from its segment."
              ::= { dot1dSrPortEntry 10 }

          dot1dSrPortApeOutFrames OBJECT-TYPE
              SYNTAX  Counter
              ACCESS  read-only





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              STATUS  mandatory
              DESCRIPTION
                      "The number of all Paths Explorer Frames, also
                      referred to as All Routes 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
                      "The number of ARE and STE 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





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                      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 }

          dot1dSrPortDupLanIdOrTreeErrors OBJECT-TYPE
              SYNTAX  Counter
              ACCESS  read-only
              STATUS  mandatory
              DESCRIPTION
                      "The number of duplicate LAN IDs or Tree errors.
                      This helps in detection of problems in networks
                      containing older IBM Source Routing Bridges."
              ::= { dot1dSrPortEntry 17 }



























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          -- scalar object in dot1dSr

          dot1dSrBridgeLfMode OBJECT-TYPE
              SYNTAX  INTEGER {
                          mode3(1),
                          mode6(2)
                      }
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "Indicates whether the bridge operates using older
                      3 bit length negotiation fields or the newer 6 bit
                      length field in its RIF."
              ::= { dot1dSr 2 }




































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          -- The Port-Pair Database

          -- Implementation of this group is optional.

          -- This group is implemented by those bridges that support the
          -- direct multiport model of the source route bridging mode as
          -- defined in the IEEE 802.5 SRT Addendum to 802.1d.

          -- Bridges implementing this group may report 65535 for
          -- dot1dSrPortBridgeNumber and dot1dSrPortTargetSegment, indicating
          -- that those objects are not applicable.

          dot1dPortPairTableSize OBJECT-TYPE
              SYNTAX  Gauge
              ACCESS  read-only
              STATUS  mandatory
              DESCRIPTION
                      "The total number of entries in the Bridge Port
                      Pair Database."
              ::= { dot1dPortPair 1 }


          -- the Bridge Port-Pair table

          -- this table represents port pairs within a bridge forming
          -- a unique bridge path, as defined in the IEEE 802.5M SRT
          -- Addendum.

          dot1dPortPairTable OBJECT-TYPE
              SYNTAX  SEQUENCE OF Dot1dPortPairEntry
              ACCESS  not-accessible
              STATUS  mandatory
              DESCRIPTION
                      "A table that contains information about every
                      port pair database entity associated with this
                      source routing bridge."
              ::= { dot1dPortPair 2 }

          dot1dPortPairEntry OBJECT-TYPE
              SYNTAX  Dot1dPortPairEntry
              ACCESS  not-accessible
              STATUS  mandatory
              DESCRIPTION
                      "A list of information for each port pair entity
                      of a bridge."





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              INDEX   { dot1dPortPairLowPort, dot1dPortPairHighPort }
              ::= { dot1dPortPairTable 1 }

          Dot1dPortPairEntry ::=
              SEQUENCE {
                  dot1dPortPairLowPort
                      INTEGER,
                  dot1dPortPairHighPort
                      INTEGER,
                  dot1dPortPairBridgeNum
                      INTEGER,
                  dot1dPortPairBridgeState
                      INTEGER
              }

          dot1dPortPairLowPort OBJECT-TYPE
              SYNTAX  INTEGER (1..65535)
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "The port number of the lower numbered port for
                      which this entry contains port pair database
                      information."
              ::= { dot1dPortPairEntry 1 }

          dot1dPortPairHighPort OBJECT-TYPE
              SYNTAX  INTEGER (1..65535)
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "The port number of the higher numbered port for
                      which this entry contains port pair database
                      information."
              ::= { dot1dPortPairEntry 2 }

          dot1dPortPairBridgeNum OBJECT-TYPE
              SYNTAX  INTEGER
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "A bridge number that uniquely identifies the path
                      provided by this source routing bridge between the
                      segments connected to dot1dPortPairLowPort and
                      dot1dPortPairHighPort.  The purpose of bridge
                      number is to disambiguate between multiple paths





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                      connecting the same two LANs."
              ::= { dot1dPortPairEntry 3 }

          dot1dPortPairBridgeState OBJECT-TYPE
              SYNTAX  INTEGER {
                          enabled(1),
                          disabled(2),
                          invalid(3)
                      }
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "The state of dot1dPortPairBridgeNum.  Writing
                      'invalid(3)' to this object removes the
                      corresponding entry."
              ::= { dot1dPortPairEntry 4 }




          END





























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          6.  Acknowledgments

          This document was produced on behalf of the Bridge MIB Working
          Group in the NM area of the Internet Engineering Task Force.

          The authors wish to thank the members of the Bridge MIB
          Working Group for their many comments and suggestions which
          improved this effort.










































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          7.  References

          [1]  Rose M., and K. McCloghrie, "Structure and Identification
               of Management Information for TCP/IP-based internets",
               STD 16, RFC 1155, Performance Systems International,
               Hughes LAN Systems, May 1990.

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

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

          [4]  Decker, E., Langille, P., Rijsinghani, A., and
               McCloghrie, K., "Definitions of Managed Objects for
               Bridges", RFC 1493, cisco Systems, Digital Equipment
               Corporation, Digital Equipment Corporation, Hughes LAN
               Systems.

          [5]  Rose, M., and K. McCloghrie, Editors, "Concise MIB
               Definitions", STD 16, RFC 1212, Performance Systems
               International, Hughes LAN Systems, March 1991.

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

          [7]  ANSI/IEEE Standard 802.1D-1990 MAC Bridges, IEEE Project
               802 Local and Metropolitan Area Networks, (March 8,
               1991).

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

          [9]  ISO DIS 10038 MAC Bridges.

          [10] ANSI/IEEE P802.5M-Draft 7, "Source Routing Transparent
               Bridge Operation", IEEE Project 802 (1991).

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





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          Internet Draft    Source Routing Bridge MIB           Feb 1996


          8.  Security Considerations

          Security issues are not discussed in this memo.


          9.  Authors' Address

          Eric B. Decker
          cisco Systems, Inc.
          170 West Tasman Drive,
          San Jose CA 95134
          (408) 526 8241
          cire@cisco.com

          Keith McCloghrie
          cisco Systems, Inc.
          170 West Tasman Drive,
          San Jose CA 95134
          (408) 526 5260
          kzm@cisco.com

          Paul Langille
          Ascom Nexion, Inc.
          289 Great Road
          Acton, MA 01720-4739
          (508) 266 3401
          langille@nexen.com

          Anil Rijsinghani
          Digital Equipment Corporation
          550 King Street
          Littleton, MA 01460
          (508) 486 6786
          anil@netcad.enet.dec.com
















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          Internet Draft    Source Routing Bridge MIB           Feb 1996


          Table of Contents


          1 Introduction ..........................................    2
          2 The Network Management Framework ......................    3
          2.1 Object Definitions ..................................    3
          3 Overview ..............................................    4
          3.1 Structure of MIB ....................................    4
          3.1.1 The dot1dSr Group .................................    6
          3.1.2 The dot1dPortPair Group ...........................    6
          3.2 Relationship to Other MIBs ..........................    6
          3.2.1 Relationship to the Bridge MIB ....................    6
          3.2.2 Relationship to the 'system' group ................    6
          3.2.3 Relationship to the 'interfaces' group ............    7
          4 Changes from RFC 1525 .................................    8
          5 Definitions ...........................................    9
          5.1 Groups in the SR MIB ................................    9
          5.2 The dot1dSr Group Definitions .......................   10
          5.3 The dot1dPortPair Group Definitions .................   18
          6 Acknowledgments .......................................   21
          7 References ............................................   22
          8 Security Considerations ...............................   23
          9 Authors' Address ......................................   23



























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