1、IEEE Std 802.1ag-2007(Amendment toIEEE Std 802.1Q-2005as amended byIEEE Std 802.1ad-2005and IEEE Std 802.1ak-2007)IEEE Standard forLocal and metropolitan area networksVirtual Bridged Local Area Networks Amendment 5: Connectivity Fault ManagementIEEE3 Park Avenue New York, NY 10016-5997, USA17 Decemb
2、er 2007IEEE Computer SocietySponsored by theLAN/MAN Standards Committee802.1agTMIEEE Std 802.1ag-2007(Amendment toIEEE Std 802.1Q-2005as amended byIEEE Std 802.1ad-2005and IEEE Std 802.1ak-2007)IEEE Standard forLocal and metropolitan area networksVirtual Bridged Local Area NetworksAmendment 5:Connec
3、tivity Fault ManagementSponsor LAN/MAN Standards Committeeof theIEEE Computer SocietyApproved 27 September 2007IEEE SA-Standards BoardThe Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2007 by the Institute of Electrical and Electronics En
4、gineers, Inc.All rights reserved. Published 17 December 2007. Printed in the United States of America.IEEE and 802 are registered trademarks in the U.S. Patent +1 978 750 8400. Permission to photocopy portions ofany individual standard for educational classroom use can also be obtained through the C
5、opyright ClearanceCenter.iv Copyright 2007 IEEE. All rights reserved.IntroductionThe MAC Bridge standardization activities that resulted in the development of IEEE Std 802.1Dintroduced the concept of Filtering Services in Bridged Local Area Networks, mechanisms whereby filteringinformation in such L
6、ANs can be acquired and held in a Filtering Database, as well as support for expediteddata, dynamic filtering of Group MAC addresses through the GMRP protocol, and the GARP protocol thatsupports GMRP and can support other applications.IEEE Std 802.1Q-2005, a revision of IEEE Std 802.1Q-1998, defines
7、 mechanisms that allow theimplementation of Virtual Bridged Local Area Networks, including:a) Virtual LAN Services;b) The operation of the Forwarding Process that is required;c) The structure of the Filtering Database that is required;d) The nature of the protocols and procedures that are required i
8、n order to provide Virtual LANservices, including the definition of the frame formats used to represent VLAN identificationinformation, and the procedures used in order to insert and remove VLAN identifiers and theheaders in which they are carried;e) The ability to support end-to-end signaling of pr
9、iority information regardless of the intrinsic abilityof the underlying MAC protocols to signal priority information;f) The GARP VLAN Registration Protocol (GVRP) that allows distribution and registration of VLANmembership information (the protocol described makes use of the GARP protocol defined in
10、 IEEEStd 802.1D);g) The management services and operations that are required in order to configure and administernetworks;h) The ability to restrict Dynamic Group and VLAN registration based on the contents of staticfiltering entries;i) VLAN classification according to link layer protocol type;j) Su
11、pport for VLANs carried over multiple Spanning Tree instances.IEEE Std 802.1ad-2005, an amendment to IEEE Std 802.1Q-2005, defines mechanisms that allow theimplementation of Provider Bridged Networks, including:k) The differentiation between Service VLANs (S-VLANs), identified by a new S-VLAN tag, a
12、ndcustomer VLANs (C-VLANs), identified by the IEEE 802.1Q tag;l) The encapsulation of C-VLAN tags within S-VLAN tags, in order to allow a service provider tocarry some or all of a customers C-VLANs within a single S-VLAN;m) The provision of two levels of drop precedence separate from the priority le
13、vels of IEEE Std802.1D, and the replacement of the Canonical Format Indicator of the C-VLAN tag by a DropEligible Indicator in the S-VLAN tag to carry the drop precedence;n) The passing of certain of the customers control PDUs, including IEEE 802.1AB LLDP PDUs andIEEE 802.1Q Bridge PDUs, transparent
14、ly through the Provider Bridged Network as ordinary data;o) The reassignment of MAC addresses used for control PDUs, including BPDUs, for use by ProviderBridges;p) The definition of C-VLAN components, added to Provider Bridge Ports to provide the functionsnecessary to support the allocation of C-VLA
15、Ns to S-VLANs, to map priorities between networks,and to interact with the customers control protocols; andq) The managed objects necessary to control these functions.This standard provides Connectivity Fault Management (CFM) capabilities useful to Virtual Bridged LocalArea Networks for detecting, i
16、solating, and reporting connectivity faults. It is aimed primarily at ProviderThis introduction is not part of IEEE Std 802.1ag-2007, IEEE Standard for Local and Metropolitan Area NetworksVirtual Bridged Local Area NetworksAmendment 5: Connectivity Fault Management.Copyright 2007 IEEE. All rights re
17、served. vBridged Networks, but is useful also for C-VLAN networks. The mechanisms defined in this standardinclude:r) The ability to configure multiple nested Maintenance Domains over a Bridged Network or anetwork of Bridged Networks, each potentially managed by a different administrative organizatio
18、n;s) The ability to configure Maintenance Associations (MAs), each identified with a singleMaintenance Domain, and on any given Bridge, a set of VLANs;t) The protocols, procedures, and CFM Protocol Data Unit (CFM PDU) formats required to detect,isolate, and report connectivity faults;u) The ability,
19、 within an MA, to configure and manage Maintenance Points (MPs) that generate andrespond to CFM PDUs; andv) The ability to command MPs to perform certain fault isolation operations, and to inspect the results.CFM is not to be confused with the Ethernet OAM capabilities described in IEEE Std 802.3, C
20、lause 57.IEEE 802.3 OAM is concerned with detecting and reporting faults on a single point-to-point IEEE 802.3LAN. IEEE Std 802.1ag-2007 is concerned with detecting, isolating, and reporting connectivity faultsspanning networks comprising multiple LANs, including LANs other than IEEE 802.3 media.Thi
21、s standard contains state-of-the-art material. The area covered by this standard is undergoing evolution.Revisions are anticipated within the next few years to clarify existing material, to correct possible errors, andto incorporate new related material. Information on the current revision state of
22、this and other IEEE 802standards can be obtained fromSecretary, IEEE-SA Standards Board445 Hoes LaneP.O. Box 1331Piscataway, NJ 08855-1331USANotice to usersErrataErrata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errat
23、a/index.html. Users are encouraged to check this URL forerrata periodically.InterpretationsCurrent interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/index.html.Patents Attention is called to the possibility that implementation of this standard may req
24、uire use of subject mattercovered by patent rights. By publication of this standard, no position is taken with respect to the existence orvalidity of any patent rights in connection therewith. A patent holder or patent applicant has filed a statementof assurance that it will grant licenses under the
25、se rights without compensation or under reasonable rates,with reasonable terms and conditions that are demonstrably free of any unfair discrimination to applicantsdesiring to obtain such licenses. Other Essential Patent Claims may exist for which a statement of assurancehas not been received. The IE
26、EE is not responsible for identifying Essential Patent Claims for which avi Copyright 2007 IEEE. All rights reserved.license may be required, for conducting inquiries into the legal validity or scope of Patents Claims, ordetermining whether any licensing terms or conditions are reasonable or non-dis
27、criminatory. Furtherinformation may be obtained from the IEEE Standards Association.ParticipantsAt the time this standard was submitted to the IEEE-SA Standards Board for approval, the following wereparticipants in the IEEE 802.1 Working Group:Anthony A. Jeffree,ChairPaul Congdon,Vice ChairStephen R
28、. Haddock, Interworking Task Group ChairNorman W. Finn,Editor-in-ChiefDavid V. Elie-Dit-Cosaque, Dinesh Mohan, Oscar Rodriguez, Ali Sajassi, Assistant EditorsThe following members of the individual balloting committee voted on this standard. Balloters may havevoted for approval, disapproval, or abst
29、ention.Alexei BeliaevJean-Michel BonnamyMike BorzaPaul BottorffRudolf BrandnerJim BurnsDirceu CavendishFrank ChaoUri CummingsRussell DietzLinda DunbarHesham ElbakouryDonald W. FedykFelix Feifei FengDavid FratturaJohn FullerGeoffrey GarnerAnoop GhanwaniKen GrewalRomain InslerRan Ish-ShalomVipin JainH
30、al KeenYongbum KimMike KoBruce KwanKari LaihonenYannick Le GoffDavid MartinJohn MessengerHiroshi OhtaDon PannellGlenn ParsonsKen PattonHaim PoratRay QiuKaren RandallRobert RodenJosef RoeseAllyn RomanowDan RomascanuJessy V. RouyerEric RyuPanagiotis SaltsidisSam SambasivanJohn M. SauerMichael J. Seama
31、nKoichiro SetoCurtis SimonsonNurit SprecherKevin B. StantonRobert SultanMuneyoshi SuzukiFrancois TalletMichael Johas TeenerJohn TerryPatricia A. ThalerDennis VolpanoManoj WadekarBert WijnenLudwig WinkelMichael D. WrightToru AiharaThomas Alexander Butch AntonHugh Barrass Tomo Bogataj Matthew Burnburg
32、 Edward J. Carley James T. Carlo Juan C. Carreon Keith ChowBryan P. Cook Tommy P. Cooper Wael W. DiabRussell S. Dietz Thomas J. Dineen Sourav K. Dutta David V. Elie-Dit-CosaqueDonald W. Fedyk Norman W. Finn C. J. Fitzgerald Yukihiro Fujimoto Devon L. Gayle Michael D. Geipel Randall C. Groves C. G. G
33、uyStephen R. Haddock John F. Hawkins David Hunter Atsushi ItoRaj JainAnthony A. Jeffree Michael D. Johas TeenerPeter G. Jones Bobby JoseShinkyo Kaku Junghong Kao Piotr Karocki Stuart J. Kerry Lior Khermosh Yongbum Kim Cees KlikThomas M. Kurihara Copyright 2007 IEEE. All rights reserved. viiWhen the
34、IEEE-SA Standards Board approved this standard on 27 September 2007, it had the followingmembership:Steve M. Mills,ChairRobert M. Grow, Vice ChairDon Wright,Past ChairJudith Gorman,Secretary*Member EmeritusAlso included are the following nonvoting IEEE-SA Standards Board liaisons:Satish K. Aggarwal,
35、 NRC RepresentativeAlan H. Cookson, NIST RepresentativeMichelle D. TurnerIEEE Standards Program Manager, Document DevelopmentMichael D. KipnessIEEE Standards Program Manager, Technical Program DevelopmentJeremy Landt Juan L. Lazaro John LemonG. LuriArthur Marris Marco Mascitto Jonathon C. Mclendon R
36、ichard I. Mellitz Gary L. Michel Dinesh Mohan Jose Morales Michael S. Newman Paul Nikolich Satoshi Obara Robert OHara Stephen R. Palm Vikram PunjJose Puthenkulam Maximilian Riegel Robert A. Robinson Fernando Lucas Rodriguez Jessy V. Rouyer John M. Sauer Bartien Sayogo Thomas Schossig Michael J. Seam
37、anAmjad A. Soomro Matthew B. Squire Manikantan Srinivasan Thomas E. Starai Walter Struppler Alourdes T. Sully Robert Sultan Joseph J. Tardo Patricia A. Thaler Mark-Rene Uchida Stanley S. Wang Stephen C. Webb Oren YuenJanusz ZalewskiRichard DeBlasioAlex GelmanWilliam R. GoldbachArnold M. GreenspanJoa
38、nna N. GueninJulian Forster*Kenneth S. HanusWilliam B. HopfRichard H. HulettHermann KochJoseph L. Koepfinger*John KulickDavid J. LawGlenn ParsonsRonald C. PetersenTom A. PrevostNarayanan RamachandranGreg RattaRobby RobsonAnne-Marie SahaziziaVirginia C. SulzbergerMalcolm V. ThadenRichard L. TownsendH
39、oward L. Wolfmanviii Copyright 2007 IEEE. All rights reserved.FiguresFigure 6-1MAC entities, the MAC Service, and MAC Service users (clients). 14Figure 6-2An interface stack 15Figure 6-3Two back-to-back EISS Multiplex Entities 18Figure 12-1Relationships among CFM managed objects 24Figure 18-1One Mai
40、ntenance Domain: operators view . 119Figure 18-2One service instance: operators view. 120Figure 18-3One service instance: customers view . 120Figure 18-4MEP and MIP Symbols. 121Figure 18-5Maintenance Associations: one service instance in a provider network. 122Figure 18-6Maintenance Associations: Ex
41、pansion of Figure 18-5 123Figure 18-7MEPs, MIPs, and MD Levels . 124Figure 19-1CFM Protocol shims . 125Figure 19-2Maintenance association End Point (MEP). 128Figure 19-3MIP Half Function 133Figure 19-4Linktrace Output Multiplexer shim. 135Figure 19-5Linktrace Output Multiplexer architecture 135Figur
42、e 20-1MEP state machinesoverview and relationships. 146Figure 20-2MEP Continuity Check Initiator state machine 152Figure 20-3MHF Continuity Check Receiver state machine. 153Figure 20-4MEP Continuity Check Receiver state machine . 156Figure 20-5Remote MEP state machine 158Figure 20-6Remote MEP Error
43、state machine. 159Figure 20-7MEP Cross Connect state machine . 160Figure 20-8MP Loopback Responder state machine. 162Figure 20-9MEP Loopback Initiator transmit state machine. 164Figure 20-10MEP Loopback Initiator receive state machine 165Figure 20-11MEP Fault Notification Generator state machine . 1
44、67Figure 20-12MEP Linktrace Initiator receive state machine. 171Figure 20-13Linktrace Responder, MEPs, MHFs, and LOMs 173Figure 20-14LTM Receiver state machine 178Figure 20-15LTR Transmitter state machine. 179Figure 22-1MEPs and MIPs distinguished by VID (incomplete picture) 208Figure 22-2Alternate
45、view of Forwarding process 209Figure 22-3Combining per-VLAN Maintenance Points into two shims. 210Figure 22-4More complete picture of Maintenance Point placement in a Bridge Port. 211Figure 22-5Service instance spanning two Bridges protected by Up MPs 213Figure 22-6Service instance spanning two Brid
46、ges protected by Down MPs. 213Figure 22-7Maintenance Point placement in a non-VLAN aware Bridge Port. 215Figure 22-8Maintenance Point placement relative to other standards. 216Figure 22-9Creating MEPs and MIPs 219Figure 22-10CFM in a Provider Edge Bridge C-tagged service interface. 225Figure 22-11Up
47、 MEPs in a Management Port. 226Figure 22-12CFM in the enterprise environment 227Figure 22-13CFM on a Bridge conformant to IEEE Std 802.1Q-2005. 228Figure J.1Up MPs in a CFM Port 244Copyright 2007 IEEE. All rights reserved. ixTablesTable 8-9Continuity Check Message Group Destination MAC Addresses. 22
48、Table 8-10Linktrace Message Group Destination MAC Addresses 22Table 17-1Correspondence between variables, managed objects, and MIB objects. 43Table 17-2Sensitive managed objects: tables and notifications 50Table 17-3Sensitive managed objects: variables in dot1agCfmMdTable . 50Table 19-1Actions taken
49、 by MP OpCode Demultiplexers 129Table 19-2Received destination_address filtering by CFM entities 134Table 19-3SAP use for Linktrace Messages and Linktrace Replies 136Table 20-1Fault Alarm defects and priorities 140Table 20-2Deriving enableRmepDefect and Port Status TLV in a Bridge . 149Table 21-1CFM PDU Encapsulation: Type/Length Media. 186Table 21-2CFM PDU Encapsulation: LLC Media 186Table 21-4OpCode Field range assignments . 187Table 21-3Common CFM Header format 187Table 21-5TLV format. 188Table
