IS-IS Minimum Remaining Lifetime
RFC 7987
Document | Type | RFC - Proposed Standard (October 2016; No errata) | |
---|---|---|---|
Authors | Les Ginsberg , Paul Wells , Bruno Decraene , Tony Przygienda , Hannes Gredler | ||
Last updated | 2016-10-19 | ||
Replaces | draft-ginsberg-isis-remaining-lifetime | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Christian Hopps | ||
Shepherd write-up | Show (last changed 2016-05-25) | ||
IESG | IESG state | RFC 7987 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Alia Atlas | ||
Send notices to | "Christian Hopps" <chopps@chopps.org> | ||
IANA | IANA review state | IANA OK - No Actions Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) L. Ginsberg Request for Comments: 7987 P. Wells Category: Standards Track Cisco Systems ISSN: 2070-1721 B. Decraene Orange T. Przygienda Juniper H. Gredler RtBrick Inc. October 2016 IS-IS Minimum Remaining Lifetime Abstract Corruption of the Remaining Lifetime field in a Link State Protocol Data Unit (LSP) can go undetected. In certain scenarios, this may cause or exacerbate flooding storms. It is also a possible denial- of-service attack vector. This document defines a backwards- compatible solution to this problem. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7987. Ginsberg, et al. Standards Track [Page 1] RFC 7987 IS-IS Remaining Lifetime October 2016 Copyright Notice Copyright (c) 2016 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 Simplified BSD License. Table of Contents 1. Problem Statement ...............................................3 1.1. Requirements Language ......................................4 2. Solution ........................................................4 3. Deployment Considerations .......................................5 3.1. Inconsistent Values for MaxAge .............................5 3.2. Reporting Corrupted Lifetime ...............................6 3.3. Impact of Delayed LSP Purging ..............................7 4. Security Considerations .........................................7 5. References ......................................................7 5.1. Normative References .......................................7 5.2. Informative References .....................................8 Acknowledgements ...................................................8 Contributors .......................................................8 Authors' Addresses .................................................9 Ginsberg, et al. Standards Track [Page 2] RFC 7987 IS-IS Remaining Lifetime October 2016 1. Problem Statement [ISO10589] defines the format of a Link State PDU (LSP) that includes a Remaining Lifetime field. This field is set by the originator based on local configuration and then decremented by all systems once the entry is stored in their LSP Database (LSPDB) consistent with the passing of time. This allows all Intermediate Systems (ISs) to age out the LSP at approximately the same time. Each LSP also has a checksum field to allow receiving systems to detect errors that may have occurred during transmission. [ISO10589] mandates that the checksum is calculated by the originator of the LSP and cannot be modified by other routers. Therefore, the Remaining Lifetime is deliberately excluded from the checksum calculation. In cases where cryptographic authentication is included in an LSP ([RFC5304] or [RFC5310]), the Remaining Lifetime field is also excluded from the hash calculation. If the Remaining Lifetime field gets corrupted during flooding, this corruption is therefore undetectable. The consequences of such corruption depend upon how the Remaining Lifetime is altered. In cases where the Remaining Lifetime becomes larger than theShow full document text