Internet Engineering Task Force S. Setty Internet-Draft Huawei Technologies India Pvt. Intended status: Standards Track Ltd. Expires: September 5, 2012 T. Tsou, Ed. Huawei Technologies (USA) March 4, 2012 Update to the processing of the Hop-by-Hop Options extension header draft-tsou-6man-hbh-header-update-00 Abstract The Hop-by-Hop Options header is used to convey optional information that must be examined by every node along a packet's delivery path. This document updates RFC2460, removing the requirement that source nodes must process the Hop-by-Hop extension header, on the basis that it imposes a performance impact with no advantages. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 5, 2012. Copyright Notice Copyright (c) 2012 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 Setty & Tsou Expires September 5, 2012 [Page 1] Internet-Draft HBH Options Header Update March 2012 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3 2. Processing of Hop-by-Hop Option Header . . . . . . . . . . . . 3 3. Updating RFC2460 . . . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. Normative References . . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 4 Setty & Tsou Expires September 5, 2012 [Page 2] Internet-Draft HBH Options Header Update March 2012 1. Introduction The Hop-by-Hop Options extension header is used to convery information that must be examined by all nodes along the path. [RFC2460] requires processing of the Hop-by-Hop Options extension header in all nodes along the packet delivery path. However, this is not really necessary for source node, and imposes a performance penalty on the source node when such packets are employed. Section 2 describes the Processing of Hop-by-hop Options header. Section 3 formally updates the [RFC2460] such that the aforementioned penalty on the source node is eliminated. 1.1. 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 RFC 2119 [RFC2119]. 2. Processing of Hop-by-Hop Option Header Section 4 of [RFC2460] states that the Hop-by-Hop Options header must be examined and processed by every node along a packet's delivery path, including the source and destination nodes. The above requirement means that a node originating the packet that contains a Hop-by-Hop Extension header will have to process that header. Since source node is the one inserting the header in the first place, there does not seem to be any advantages in such requirement, but otherwise represents a performance penalty. As of the time of this writing, two options (other than the padding options) have been specified for the Hop-by-Hop Options extension header: Router Alert Option This option is defined in [RFC2711], intended for applications like MLD, RSVP, etc. Jumbo Payload Option This option is defined in [RFC2675], and used to convey IPv6 payloads larger than 2^16 bytes. In the above two cases, the source node does not need to process the Hop-By-Hop options extension header. Setty & Tsou Expires September 5, 2012 [Page 3] Internet-Draft HBH Options Header Update March 2012 3. Updating RFC2460 This document updates [RFC2460] as follows: The Hop-by-Hop Options header MUST be examined and processed by every node along a packet's delivery path (including the destination nodes), except for the source node. 4. IANA Considerations This specification does not require any IANA actions. 5. Security Considerations This specification does not introduce new security issues. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [RFC2675] Borman, D., Deering, S., and R. Hinden, "IPv6 Jumbograms", RFC 2675, August 1999. [RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast Listener Discovery (MLD) for IPv6", RFC 2710, October 1999. [RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", RFC 2711, October 1999. [RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery Version 2 (MLDv2) for IPv6", RFC 3810, June 2004. Setty & Tsou Expires September 5, 2012 [Page 4] Internet-Draft HBH Options Header Update March 2012 Authors' Addresses Sreenatha Setty Huawei Technologies India Pvt. Ltd. Airport Road Bangalore 560008 India Phone: +91 961 127 9232 Email: sreenathabs@huawei.com Tina Tsou (editor) Huawei Technologies (USA) 2330 Central Expressway Santa Clara CA 95050 USA Phone: +1 408 330 4424 Email: tina.tsou.zouting@huawei.com Setty & Tsou Expires September 5, 2012 [Page 5]