Network Working Group S. Madanaplli INTERNET DRAFT S. Kumar <draft-syam-ipv6-state-model-00.txt> O.L.N. Rao Expires: April 2004 S. Park Category:Informational SAMSUNG October 2003 State Model for IPv6 Interfaces Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 draft documents 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 "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document specifies a generic flexible state model for IPv6 Interfaces. Syam, et. al. Expires April 2003 [Page 1]
Internet-Draft State Model for IPv6 Interfaces May 2003 Table of Contents 1. Introduction ............................................. 3 2. Terminology .............................................. 3 3. State Model .............................................. 3 3.1. Interface States ......................................... 4 3.1.1. Primary State ............................................ 4 3.1.2. Primary State Qualifier .................................. 4 3.1.3. Secondary State .......................................... 5 3.1.4. Secondary State Qualifier ................................ 6 3.2. Events ................................................... 6 3.2.1. Management Events ........................................ 6 3.2.2. Lower Layer Events ....................................... 6 3.2.3. Autonomous Events ........................................ 7 3.3. Dependencies among states ................................ 7 3.4. State Transition Diagram ................................. 8 3.5. State Transition Table ................................... 9 4. Security Considerations .................................. 11 5. References ............................................... 11 6. Acknowledgements ......................................... 11 7. Authors' Addresses ....................................... 12 8. Intellectual Property Statement .......................... 12 9. Full Copyright Statement ................................. 13 Syam, et. al. Expires April 2003 [Page 2]
Internet-Draft State Model for IPv6 Interfaces May 2003 1. Introduction This document defines a state model for IPv6 Interfaces. This state model facilitates the administrator to know the current status of the IPv6 interface at any instant and provides information about what actions the administrator may need to take to bring the interface UP, if it is currently unavailable for performing the provisioned services. Any entity in any layered architecture can be DOWN (non-functional) because of the following three reasons: o The management (administrator) explicitly prevented in performing the assigned services. o The lower layer is not providing its assigned services. o There is an internal fault in the entity itself. At any instant, there can be multiple reasons (the combination of the above) because of which the entity may be non-functional. This document captures all the states an IPv6 interface may under go because of the above mentioned reasons. The State Model defined in this document is flexible in the sense that one can define their own reasons/fault conditions for the IPv6 interfaces depending on their needs. The State Model described here is based on the Control State Machine that has been implemented in Samsung's IPv6 Protocol Stack. 2. Terminology Primary State (PST) Indicates the current overall service condition of an entity. Primary State Qualifier (PSTQ) This gives further information about why the entity is in a particular PST. Secondary State (SST) Provides additional information relevant to state management. Syam, et. al. Expires April 2003 [Page 3]
Internet-Draft State Model for IPv6 Interfaces May 2003 3. State Model The State of an entity consists of Operational State and Administrative State. The Operational State indicates whether the entity is capable of providing its provisioned functions. The Administrative State indicates whether it is administratively inhibited from providing its provisioned functions. The Primary State provides the overall service condition of the entity which will be qualified by the Primary State Qualifier. The secondary State and its Qualifiers provide further information why the entity is not able to provide its assigned services. 3.1. Interface States 3.1.1. Primary State Primary State indicates the overall service condition of the entity, whether it is UP (In-Service), or DOWN (Out-of-Service). UP The entity is partially or fully operable to provide some or all of its assigned services to the users. The entity is operationally capable and at the same time administratively allowed to provide its services. That is, both the operational and administrative states are UP. DOWN The entity is totally inoperable and unable to provide any of its assigned services to the users. The PSTQ value will qualify the unavailability of the entity. For example, whether it is operationally incapable or administratively inhibited from providing its services. 3.1.2. Primary State Qualifier The following values of PSTQ qualify the PST value DOWN. AU (Autonomous) Operational State is DOWN. MA (Management) Administrative State is DOWN. AUMA (Autonomous-and-Management) Both Operational and Administrative States are DOWN. Syam, et. al. Expires April 2003 [Page 4]
Internet-Draft State Model for IPv6 Interfaces May 2003 Autonomous (AU) The entity is incapable of providing any of its services, and there is no external administrative restriction inhibiting the entity from providing these services. In general, the cause of incapability is an unsolicited event occurrence on the Interface. Examples of such events include, but not limited to a defect developed in the entity, its Lower Layer (Supporting Entity) is DOWN or the Interface ID is duplicate incase of IPv6 Interface etc. Management (MA) The entity is intentionally suspended by the external management command from providing all of its services. In this state the entity itself is still operationally capable of, even though it is currently being suspended from providing service. While resident in this state, updates of providing service, data, and testing and maintenance activities are permitted. Fault detection shall be continued in this state, however no reports will be generated to the management. AUMA (Autonomous-and-Management) The entity is incapable of providing services, and at the same time it has been intentionally suspended from providing all of its services. While resident in this state, updates of provisioning data and Testing and maintenance activities are permitted. Fault detection shall be continued to determine if an operational problem has been corrected or an additional operational problem has occurred. 3.1.3. Secondary State The following are the SST values that a stack entity can have: UAS (Unassigned) The IPv6 interface has not been assigned with the necessary provisioning data. That is the IPv6 Interface does not exist. No SSTQs have been defined for this SST. LLD (Lower Layer Down) The associated lower layer entity (Layer 2) is DOWN. No SSTQs have been defined for this SST. LLD (Lower Layer Association Down) The associated lower layer entity (Layer 2) Association is DOWN. No SSTQs have been defined for this SST. Syam, et. al. Expires April 2003 [Page 5]
Internet-Draft State Model for IPv6 Interfaces May 2003 FLT (Internal Fault) The stack entity itself has got some fault that inhibited it from providing services. NORS and DIID have been defined as SSTQs for this SST. 3.1.4. Secondary State Qualifier Currently the following SSTQs have been defined. Implementers can define their own SSTQs based on their requirements. NORS Stack entity is out of resources. DIID The interface identifier is Duplicate. 3.2. Events 3.2.1. Management Events ADMIN-LOCK Management inhibited the interface from providing services. ADMIN_UNLOCK Management permitted interface to provide services. CREATE Create an IPv6 Interface. DELETE Remove an IPv6 Interface. 3.2.2. Lower Layer Events LLD The Lower Layer is DOWN. LLU The Lower Layer is UP. LLAD The Lower Layer Association is DOWN. LLAU The Lower Layer Association is UP. Syam, et. al. Expires April 2003 [Page 6]
Internet-Draft State Model for IPv6 Interfaces May 2003 3.2.3. Autonomous Events RESOURCE REQUEST FAILED The request for a particular of resource that is required for the interface to be functional is FAILED. DAD FAILED Duplicate IID Detection FAILED. DAD FAIL RECOVER Duplicate IID Detection for the new IID is SUCCEEDED after Management intervention or by some other mechanism. 3.3. Dependencies among states The following are the possible combination of Operational and Administrative State values. DOWN and Locked (DOWN, AUMA) The resource is totally inoperable, and it is also administratively prohibited from providing service. To make it available for use, both management permission (an unlock operation) and some corrective action are necessary. UP and Locked (DOWN, MA) The resource is partially or fully operable, but is administratively prohibited from providing service. To make it available for use, only management permission (an unlock operation) is required. DOWN and Unlocked (DOWN, AU) The resource is totally inoperable, but it is not administratively prohibited from providing service. To make it available for use, some corrective action is required. UP and Unlocked (UP) The resource is partially or fully operable, and is not administratively prohibited from providing service. Syam, et. al. Expires April 2003 [Page 7]
Internet-Draft State Model for IPv6 Interfaces May 2003 3.4. State Transition Diagram The following is the simplified view of the state machine for IPv6 Interfaces. The diagram does not take care of all possible state transitions from different states. +---------+ +---------+ | | | | | |---ADMIN_LOCK--->| | |DOWNN,AU,| | DOWN, | | FLT |<--ADMIN_UNLOCK--| AUMA,FLT| | | | | +---------+ +---------+ | ^ ^ ^ | | | | | | | | RECOVER | | RECOVER | | | + | | | | | | | | | FAULT FAULT | | | | | v | | v +---------+ +---------+ +---------+ | | | | | | | |--CREATE-->| |---ADMIN_LOCK--->| | | UAS | | UP | | DOWN,MA | | |<--DELETE--| |<--ADMIN_UNLOCK--| | | | | | | | +---------+ +---------+ +---------+ | ^ | ^ | | | | | | | | LLD | LLD | | | | | | | | | | LLU | LLU | | | | | | | | | | | | V | V | +---------+ +---------+ | | | | | |---ADMIN_LOCK--->| | | DOWNN, | | DOWN, | | AU,LLD |<--ADMIN_UNLOCK--| AUMA,LLD| | | | | +---------+ +---------+ Syam, et. al. Expires April 2003 [Page 8]
Internet-Draft State Model for IPv6 Interfaces May 2003 3.5. State Transition Table +---------------+--------------+---------------+-----------------------+ | Current | | Next | Actions | | State | Event | State | to be taken | +---------------+--------------+---------------+-----------------------+ | UAS | CREATE | UP | Create Interface | | | | | and Make it UP | +---------------+--------------+---------------+-----------------------+ | UP | ADMIN_LOCK | DOWN,MA | Set Admin Flag | +---------------+--------------+---------------+-----------------------+ | UP | LLD | DOWN,AU,LLD | Clear Lower Layer flag| +---------------+--------------+---------------+-----------------------+ | UP | LLAD | DOWN,AU,LLAD | Clear Association flag| +---------------+--------------+---------------+-----------------------+ | UP | FAULT | DOWN,AU,FLT | Set Fault flag | +---------------+--------------+---------------+-----------------------+ | DOWN,MA | ADMIN_UNLOCK | UP | Clear Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,MA | LLD | DOWN,AUMA,LLD | Clear Lower Layer flag| +---------------+--------------+---------------+-----------------------+ | DOWN,MA | LLAD | DOWN,AUMA,LLAD| Clear Association flag| +---------------+--------------+---------------+-----------------------+ | DOWN,MA | FAULT | DOWN,AUMA,FLT | Set Fault flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,LLD | ADMIN_LOCK | DOWN,AUMA,LLD | Set Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,LLD | LLU | UP | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,LLD | ADMIN_UNLOCK | DOWN,AU,LLD | Clear Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,LLD | LLU | DOWN,MA | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,LLAD | ADMIN_LOCK | DOWN,AUMA,LLAD| Set Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,LLAD | LLAU | UP | Set Association Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,LLAD| ADMIN_UNLOCK | DOWN,AU,LLAD | Clear Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,LLAD| LLAU | DOWN,MA | Set Association Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,FLT | ADMIN_LOCK | DOWN,AUMA,FLT | Set Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,FLT | RECOVER(LLU) | UP | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,FLT | RECOVER(LLD) | DOWN,AU,LLD | Clear Lower Layer Flag| +---------------+--------------+---------------+-----------------------+ Syam, et. al. Expires April 2003 [Page 9]
Internet-Draft State Model for IPv6 Interfaces May 2003 +---------------+--------------+---------------+-----------------------+ | DOWN,AU,FLT | RECOVER(LLAU)| UP | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AU,FLT | RECOVER(LLAD)| DOWN,AU,LLAD | Clear Association Flag| +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,FLT | ADMIN_UNLOCK | DOWN,AU,FLT | Clear Admin Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,FLT | RECOVER(LLU) | DOWN,MA | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,FLT | RECOVER(LLD) | DOWN,AUMA,LLD | Clear Lower Layer Flag| +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,FLT | RECOVER(LLAU)| DOWN,MA | Set Lower Layer Flag | +---------------+--------------+---------------+-----------------------+ | DOWN,AUMA,FLT | RECOVER(LLAD)| DOWN,AUMA,LLAD| Clear Association Flag| +---------------+--------------+---------------+-----------------------+ | <AnyState> | DELETE | UAS | Lock and then Shutdown| | | | | the Interface | +---------------+--------------+---------------+-----------------------+ Syam, et. al. Expires April 2003 [Page 10]
Internet-Draft State Model for IPv6 Interfaces May 2003 4. Security Considerations CREATE/DELETE and ADMIN_LOCK/ADMIN_UNLOCK operations on an IPv6 Interface may be considered sensitive or vulnerable in some network environments. The support for such operations in a non-secure environment without proper protection can have a negative effect on network operations. SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the state attributes defined in this document. It is recommended that the implementers consider the security features as provided by the SNMPv3 framework when giving access to remote entity using SNMP. Specifically, the use of the User- based Security Model RFC 2574 and the View-based Access Control Model RFC 2575 is recommended. It is then a customer/user responsibility to ensure that the SNMP entity giving access to the state attributes defined in this document, is properly configured to give access to the attributes only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them. 5. References [1] Chisholm, S. and Perkins, D., "Entity State MIB", draft-ietf-entmib-state-00.txt, January 2003. [2] McCloghrie, K. and F. Kastenholz, "The Interface Group MIB", RFC 2863, June 2000. [3] ITU Recommendation X.731, "Information Technology - Open Systems Interconnection - System Management: State Management Function", 1992 6. Acknowledgement The authors would like to thank Margaret Wasserman and Andy Bierman for their comments on this draft. Syam, et. al. Expires April 2003 [Page 11]
Internet-Draft State Model for IPv6 Interfaces May 2003 7. Authors' Addresses Syam Madanapalli Network Systems Division, SAMSUNG India Software Operations, INDIA Phone: +91-80-51197777 Email:syam@samsung.com O.L.N. Rao Network Systems Division, SAMSUNG India Software Operations, INDIA Phone: +91-80-51197777 Email:olnrao@samsung.com Suraj Kumar Network Systems Division, SAMSUNG India Software Operations, INDIA Phone: +91-80-51197777 Email:suraj@samsung.com Soohong Daniel Park Mobile Platform Laboratory, SAMSUNG Electronics Phone: +82-31-200-4508 Email:soohong.park@samsung.com 8. Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Syam, et. al. Expires April 2003 [Page 12]
Internet-Draft State Model for IPv6 Interfaces May 2003 9. Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Funding for the RFC editor function is currently provided by the Internet Society. Syam, et. al. Expires April 2003 [Page 13]