IS-IS Working Group F. Wei Internet-Draft Y. Qin Updates: 5304, 5310 Z. Li (if approved) China Mobile Intended status: Standards Track T. Li Expires: September 9, 2010 Cisco Systems, Inc. J. Dong Huawei Technologies March 8, 2010 Purge Originator Identification TLV for IS-IS draft-wei-isis-tlv-03 Abstract At present an IS-IS purge does not contain any information identifying the Intermediate System (IS) that generates the purge. This makes it difficult to locate the source IS. To address this issue, this document defines a TLV to be added to purges to record the system ID of the IS generating it. Since normal LSP flooding does not change LSP contents, this TLV should propagate with the purge. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. 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. This Internet-Draft will expire on September 9, 2010. Wei, et al. Expires September 9, 2010 [Page 1] Internet-Draft Purge Originator Identification TLV March 2010 Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements Language . . . . . . . . . . . . . . . . . . . . . 3 3. Cases to Generate Purge Packet . . . . . . . . . . . . . . . . 3 4. The Purge Originator Identification TLV . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4 8. Normative References . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Wei, et al. Expires September 9, 2010 [Page 2] Internet-Draft Purge Originator Identification TLV March 2010 1. Introduction The IS-IS [ISO 10589] routing protocol has been widely used in large- scale IP networks because of its strong scalability and fast convergence. The IS-IS protocol floods purges throughout an area, regardless of which IS initiated the purge. If a network operator would like to investigate the cause of the purge, it is difficult to determine the origin of the purge. At present the IS-IS protocol has no mechanism to locate the originator of a purge. To address this problem, this document defines a TLV to be added to purges to record the system ID of the IS generating the purge. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Cases to Generate Purge Packet In IS-IS there are three legitimate reasons for an IS to generate a purge: 1. An IS purges its own LSP. 2. A LSP owned by another IS ages out. 3. A new DIS is elected. Field experience has observed serveral other circumstances where an IS can improperly generate a purge: 1. An implementation misunderstanding [ISO 10589] or predating TC1 generates a purge when it receives a corrupted LSP. 2. An implementation with bugs tries to purge one of its LSPs and makes a truly egregious mistake. 3. An implementation fails to retain the LSP header after purging while flooding is still in progress. Wei, et al. Expires September 9, 2010 [Page 3] Internet-Draft Purge Originator Identification TLV March 2010 4. The Purge Originator Identification TLV This document defines a TLV to be included in purges. This TLV carries the system ID of the IS generating the purge. This allows ISs receiving purges to log the system ID of the originator. This makes it much easier for the network adminstrator to locate the origin of the purge and thus the cause of the purge. Similarly, this TLV is helpful to develpers in lab situations. The Purge Originator Identification TLV is defined as: CODE - XX (to be assigned) LENGTH - total length of the value field. VALUE - System ID of the Intermediate System that initiated the purge. 5. Security Considerations If the proposed TLV is used in conjunction with IS-IS authentication mechanisms [RFC5304][RFC5310], the purge LSP is constructed by removing the original contents of the LSP, leaving only the LSP header, adding the Purge Originator Identification TLV and then adding the IS-IS authentication TLV. This document amends the behavior specified in [RFC5304] and [RFC5310]. 6. IANA Considerations RFC EDITOR NOTE: This section to be removed upon publication. This document requests that IANA assign a code point for this TLV from the IS-IS 'TLV Codepoints Registry'. 7. Acknowledgments Many thanks to Adrian Farrel and Daniel King for your comments to improve this document and move it forward. The first version of this document was mainly composed by Lianyuan Li. Acknowledgments to the discussion in the mailing list. Some impovements of this document are based on the discussion. Wei, et al. Expires September 9, 2010 [Page 4] Internet-Draft Purge Originator Identification TLV March 2010 8. Normative References [ISO 10589] ISO, "Intermediate system to Intermediate system routeing information exchange protocol for use in conjunction with the Protocol for providing the Connectionless-mode Network Service (ISO 8473)", ISO/IEC 10589:2002. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic Authentication", RFC 5304, October 2008. [RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., and M. Fanto, "IS-IS Generic Cryptographic Authentication", RFC 5310, February 2009. Authors' Addresses Fang Wei China Mobile No. 29, Financial Street, Xicheng District Beijing 100032 P.R. China Email: weifang@chinamobile.com Yue Qin China Mobile No. 29, Financial Street, Xicheng District Beijing 100032 P.R. China Email: qinyue@chinamobile.com Zhenqiang Li China Mobile Unit2, Dacheng Plaza, No. 28 Xuanwumenxi Ave, Xuanwu District Beijing 100053 P.R. China Email: lizhenqiang@chinamobile.com Wei, et al. Expires September 9, 2010 [Page 5] Internet-Draft Purge Originator Identification TLV March 2010 Tony Li Cisco Systems, Inc. 170 W. Tasman Dr. San Jose, CA 95134 USA Email: tony.li@tony.li Jie Dong Huawei Technologies KuiKe Building, No.9 Xinxi Rd., Haidian District Beijing 100085 P.R. China Email: dongjie_dj@huawei.com Wei, et al. Expires September 9, 2010 [Page 6]