Network Working Group E. Bell Request for Comments: 2674 3Com Corp. Category: Standards Track A. Smith Extreme Networks P. Langille Newbridge Networks A. Rijhsinghani Cabletron Systems K. McCloghrie cisco Systems August 1999 Definitions of Managed Objects for Bridges with Traffic Classes, Multicast Filtering and Virtual LAN Extensions Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. 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 two MIB modules for managing the new capabilities of MAC bridges defined by the IEEE 802.1D-1998 MAC Bridges and the IEEE 802.1Q-1998 Virtual LAN (VLAN) standards for bridging between Local Area Network (LAN) segments. One MIB module defines objects for managing the 'Traffic Classes' and 'Enhanced Multicast Filtering' components of IEEE 802.1D-1998. The other MIB module defines objects for managing IEEE 802.1Q VLANs. Provisions are made for support of transparent bridging. Provisions are also made so that these objects apply to bridges connected by subnetworks other than LAN segments. This memo also includes several MIB modules in a manner that is compliant to the SMIv2 [V2SMI]. This memo supplements RFC 1493 [BRIDGEMIB] and (to a lesser extent) RFC 1525 [SBRIDGEMIB]. Bell, et al. Standards Track [Page 1] RFC 2674 Bridge MIB Extensions August 1999 Table of Contents 1 The SNMP Management Framework ................................... 3 2 Overview ........................................................ 4 2.1 Scope ......................................................... 4 3 Structure of MIBs ............................................... 5 3.1 Structure of Extended Bridge MIB module ....................... 5 3.1.1 Relationship to IEEE 802.1D-1998 Manageable Objects ......... 6 3.1.2 Relationship to IEEE 802.1Q Manageable Objects .............. 8 3.1.3 The dot1dExtBase Group ...................................... 8 3.1.4 The dot1dPriority Group ..................................... 9 3.1.5 The dot1dGarp Group ......................................... 9 3.1.6 The dot1dGmrp Group ......................................... 9 3.1.7 The dot1dTpHCPortTable ...................................... 9 3.1.8 The dot1dTpPortOverflowTable ................................ 9 3.2 Structure of Virtual Bridge MIB module ........................ 9 3.2.1 Relationship to IEEE 802.1Q Manageable Objects .............. 9 3.2.2 The dot1qBase Group .........................................13 3.2.3 The dot1qTp Group ...........................................13 3.2.4 The dot1qStatic Group .......................................13 3.2.5 The dot1qVlan Group .........................................13 3.3 Textual Conventions ...........................................13 3.4 Relationship to Other MIBs ....................................14 3.4.1 Relationship to the 'system' group ..........................14 3.4.2 Relation to Interfaces MIB ..................................14 3.4.2.1 Layering Model ............................................15 3.4.2.2 ifStackTable ..............................................16 3.4.2.3 ifRcvAddressTable .........................................16 3.4.3 Relation to Original Bridge MIB .............................16 3.4.3.1 The dot1dBase Group .......................................16 3.4.3.2 The dot1dStp Group ........................................17 3.4.3.3 The dot1dTp Group .........................................17 3.4.3.4 The dot1dStatic Group .....................................17 3.4.3.5 Additions to the Original Bridge MIB ......................18 4 Definitions for Extended Bridge MIB .............................18 5 Definitions for Virtual Bridge MIB ..............................39 6 Acknowledgments .................................................80 7 Security Considerations .........................................80 8 References ......................................................81 9 Authors' Addresses ..............................................84 10 Intellectual Property ..........................................85 11 Full Copyright Statement .......................................86 Bell, et al. Standards Track [Page 2] RFC 2674 Bridge MIB Extensions August 1999 1. The SNMP Management Framework The SNMP Management Framework presently consists of five major components: o An overall architecture, described in an Architecture for Describing SNMP Management Frameworks [ARCH]. o Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and described in STD 16, RFC 1155 [V1SMI], STD 16, RFC 1212 [V1CONCISE] and RFC 1215 [V1TRAPS]. The second version, called SMIv2, is described in STD 58, RFC 2578 [V2SMI], STD 58, RFC 2579 [V2TC] and STD 58, RFC 2580 [V2CONFORM]. o Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and described in STD 15, RFC 1157 [V1PROTO]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and described in RFC 1901 [V2COMMUNITY] and RFC 1906 [V2TRANS]. The third version of the message protocol is called SNMPv3 and described in RFC 1906 [V2TRANS], Message Processing and Dispatching [V3MPC] and User- based Security Model [V3USM]. o Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in STD 15, RFC 1157 [V1PROTO]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [V2PROTO]. o A set of fundamental applications described in SNMPv3 Applications [V3APPS] and the view-based access control mechanism described in View-based Access Control Model [V3VACM]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. This memo specifies a MIB module that is compliant to the SMIv2. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64). Some machine readable information in SMIv2 will be converted into textual descriptions in Bell, et al. Standards Track [Page 3] RFC 2674 Bridge MIB Extensions August 1999 SMIv1 during the translation process. However, this loss of machine readable information is not considered to change the semantics of the MIB. 2. 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. These devices are often known as 'layer 2 switches'. There are two major modes defined for this bridging: Source-Route and transparent. Source-Route bridging is described by IEEE 802.5 [802.5]. and is not discussed further in this document. The transparent method of bridging is defined by IEEE 802.1D-1998 [802.1D] which is an update to the original IEEE 802.1D specification [802.1D-ORIG]. Managed objects for that original specification of transparent bridging were defined in RFC 1493 [BRIDGEMIB]. The original IEEE 802.1D is augmented by IEEE 802.1Q-1998 [802.1Q] to provide support for 'virtual bridged LANs' where a single bridged physical LAN network may be used to support multiple logical bridged LANs, each of which offers a service approximately the same as that defined by IEEE 802.1D. Such virtual LANs (VLANs) are an integral feature of switched LAN networks. A VLAN can be viewed as a group of end-stations on multiple LAN segments and can communicate as if they were on a single LAN. IEEE 802.1Q defines port-based Virtual LANs where membership is determined by the bridge port on which data frames are received. This memo defines the objects needed for the management of port-based VLANs in bridge entities. This memo defines those objects needed for the management of a bridging entity operating in the transparent mode, as well as some objects applicable to all types of bridges. Managed objects for Source-Route bridging are defined in RFC 1525 [SRBRIDGEMIB]. 2.1. Scope This MIB includes a comprehensive set of managed objects which attempts to match the set defined in IEEE 802.1D and IEEE 802.1Q. However, to be consistent with the spirit of the SNMP Framework, a subjective judgement was made to omit the objects from those standards most 'costly' to implement in an agent and least 'essential' for fault and configuration management. The omissions are described in section 3 below. Bell, et al. Standards Track [Page 4] RFC 2674 Bridge MIB Extensions August 1999 Historical note: The original bridge MIB [BRIDGEMIB] used the following principles for determining inclusion of an object in the BRIDGE-MIB module: (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. Structure of MIBs This document defines additional objects, on top of those existing in the original BRIDGE-MIB module defined in [BRIDGEMIB]: that MIB module is to be maintained unchanged for backwards compatibility. Section 3.4.3 of the present document contains some recommendations regarding usage of objects in the original bridge MIB by devices implementing the enhancements defined here. Two MIB modules are defined here: (1) Managed objects for an extended bridge MIB module P-BRIDGE-MIB for the traffic class and multicast filtering enhancements defined by IEEE 802.1D-1998 [802.1D]. (2) Managed objects for a virtual bridge MIB module Q-BRIDGE-MIB for the Virtual LAN bridging enhancements defined by IEEE 802.1Q-1998 [802.1Q]. 3.1. Structure of Extended Bridge MIB module 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. Bell, et al. Standards Track [Page 5] RFC 2674 Bridge MIB Extensions August 1999 3.1.1. Relationship to IEEE 802.1D-1998 Manageable Objects This section contains a cross-reference to the objects defined in IEEE 802.1D-1998 [802.1D]. It also details those objects that are not considered necessary in this MIB module. Some objects defined by IEEE 802.1D-1998 have been included in the virtual bridge MIB module rather than this one: entries in dot1qTpGroupTable, dot1qForwardAllTable and dot1qForwardUnregisteredTable are required for virtual bridged LANs with additional indexing (e.g. per-VLAN, per-FDB) and so are not defined here. Instead, devices which do not implement virtual bridged LANs but do implement the Extended Forwarding Services defined by IEEE 802.1D (i.e. dynamic learning of multicast group addresses and group service requirements in the filtering database) should implement these tables with a fixed value for dot1qFdbId (the value 1 is recommended) or dot1qVlanIndex (the value 1 is recommended). Devices which support Extended Filtering Services should support dot1qTpGroupTable, dot1qForwardAllTable and dot1qForwardUnregisteredTable. Bell, et al. Standards Track [Page 6] RFC 2674 Bridge MIB Extensions August 1999 Extended Bridge MIB Name IEEE 802.1D-1998 Name dot1dExtBase Bridge dot1dDeviceCapabilities dot1dExtendedFilteringServices dot1dTrafficClasses dot1dTrafficClassesEnabled dot1dGmrpStatus .ApplicantAdministrativeControl dot1dPriority dot1dPortPriorityTable dot1dPortDefaultUserPriority .UserPriority dot1dPortNumTrafficClasses dot1dUserPriorityRegenTable .UserPriorityRegenerationTable dot1dUserPriority dot1dRegenUserPriority dot1dTrafficClassTable .TrafficClassTable dot1dTrafficClassPriority dot1dTrafficClass dot1dPortOutboundAccessPriorityTable .OutboundAccessPriorityTable dot1dPortOutboundAccessPriority dot1dGarp dot1dPortGarpTable dot1dPortGarpJoinTime .JoinTime dot1dPortGarpLeaveTime .LeaveTime dot1dPortGarpLeaveAllTime .LeaveAllTime dot1dGmrp dot1dPortGmrpTable dot1dPortGmrpStatus .ApplicantAdministrativeControl dot1dPortGmrpFailedRegistrations .FailedRegistrations dot1dPortGmrpLastPduOrigin .OriginatorOfLastPDU dot1dTp dot1dTpHCPortTable dot1dTpHCPortInFrames .BridgePort.FramesReceived dot1dTpHCPortOutFrames .ForwardOutBound dot1dTpHCPortInDiscards .DiscardInbound dot1dTpPortOverflowTable dot1dTpPortInOverflowFrames .BridgePort.FramesReceived dot1dTpPortOutOverflowFrames .ForwardOutBound dot1dTpPortInOverflowDiscards .DiscardInbound Bell, et al. Standards Track [Page 7] RFC 2674 Bridge MIB Extensions August 1999 The following IEEE 802.1D-1998 management objects have not been included in the Bridge MIB for the indicated reasons. IEEE 802.1D-1998 Object Disposition Bridge.StateValue not considered useful Bridge.ApplicantAdministrativeControl not provided per-attribute (e.g. per-VLAN, per-Group). Only per-{device,port,application} control is provided in this MIB. 3.1.2. Relationship to IEEE 802.1Q Manageabl