Internet Engineering Task Force D. Zhou, Ed. Internet-Draft Hangzhou H3C Tech. Co., Ltd. Intended status: Standards Track H. Deng Expires: June 3, 2011 China Mobile Research Institute Y. Liu Y. Shi Hangzhou H3C Tech. Co., Ltd. H. Liu Huawei Technologies Co., Ltd. I. Bhattacharya X. Xu Cisco Systems November 30, 2010 FHR Source Network Prohibition draft-zhou-pim-fhr-source-network-prohibition-00 Abstract This document proposes a multicast stream prohibition method based on FHR(First Hop Router) sending unicast PIM messages towards source which enables switch to prohibit unnecessary multicast stream towards FHR. 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 June 3, 2011. 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 Zhou, et al. Expires June 3, 2011 [Page 1] Internet-Draft FHR Source Network Prohibition November 2010 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. Zhou, et al. Expires June 3, 2011 [Page 2] Internet-Draft FHR Source Network Prohibition November 2010 1. Introduction The Protocol Independent Multicast (PIM) is now the most popular multicast routing protocol. The router on the edge of PIM routing domain is called PIM First Hop Router (FHR). PIM has four modes: Sparse Mode (SM), Dense Mode (DM), Bidirectional PIM (Bidir-PIM), Source-Specific Multicast (SSM). In many typical deployment scenarios, link layer switches which exist between multicast sources and PIM FHR have to forward all multicast streams to PIM FHR. This will lead to waste of switches' cache and link bandwidth. The problem has been discribed in detail in the draft of draft-dizhou-pim-umf-problem-statement. This document proposes a method for PIM FHR to send UNICAST PIM Prune or Join messages towards source which could be snooped by switches to stop or forward multicast streams towards FHR. Zhou, et al. Expires June 3, 2011 [Page 3] Internet-Draft FHR Source Network Prohibition November 2010 2. Terminology In this document, several words are used to signify the requirements of the specification. These words are often capitalized. 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] With respect to PIM, this document follows the terminology that has been defined in RFC 4601 [RFC4601]. Zhou, et al. Expires June 3, 2011 [Page 4] Internet-Draft FHR Source Network Prohibition November 2010 3. Protocol Description Because DF of Bidir-PIM has to always forward multicast to RP link, so Bidir-PIM has no need to refuse multicast streams. The protocol of FSNP (FHR Source Network Prohibition) is only designed for PIM SM, SSM and DM. 3.1. Protocol Description for PIM SSM When PIM FHR receives a multicast stream, it creates an entry of (S,G) if the entry did not exist. And it judges whether the (S,G) entry has out interfaces. If the (S,G) has no out interface, the PIM FHR SHALL send out an UNICAST PIM Prune message towards the multicast source. The upstream neighbor address in the message is the source address, and the destination address of the message is that of the source. The UNICAST PIM Prune message is rate-limited. When PIM FHR receives a PIM Join or IGMP Membership Report and creates the first out interface for the (S,G) entry, it SHALL send out an UNICAST PIM Join message towards source immediately. It MAY send some PIM Join messages in a high frequency for reliability. When PIM FHR receives a PIM Prune or IGMP Leave and deletes the last out interface for the (S,G) entry, then it SHALL send out UNICAST PIM Prune message towards source. Only when source address of the multicast stream is in the same network with receiving interface, or when FHR has no RPF neighbour for the (S,G) entry shall FHR send out UNICAST PIM Join or Prune message towards source. 3.2. Protocol Description for PIM SM When PIM FHR receives a multicast stream, it creates an entry of (S,G) if the entry did not exist. Then if FHR is DR it shall send register message to RP. If FHR receives register-stop messages and there is no out-interfaces for (S,G) entry, it SHALL send out an UNICAST PIM Prune message towards the multicast source. The upstream neighbor address in the message is the source address, and the destination address of the message is that of the source. The UNICAST PIM Prune message is rate-limited. When PIM FHR receives a PIM Join message or IGMP Membership Report and creates the first out interface for the (S,G) entry, it SHALL send out an UNICAST PIM Join message towards source immediately. It MAY send some PIM Join messages in a high frequency for reliability. When PIM FHR receives a PIM Prune message or IGMP Leave and deletes Zhou, et al. Expires June 3, 2011 [Page 5] Internet-Draft FHR Source Network Prohibition November 2010 the last out interface for the (S,G) entry, then it SHALL send out UNICAST PIM Prune messages towards source. Only when source address of the multicast stream is in the same network with receiving interface, or when FHR has no RPF neighbour for the (S,G) entry shall FHR send out UNICAST PIM Join or Prune message towards source. 3.3. Protocol Description for PIM DM When PIM FHR receives a multicast stream, it creates an entry of (S,G) if the entry did not exist. Then FHR shall send multicast stream to all downstream interfaces. If FHR receives PIM Prune messages and there is no out-interface to forward multicast stream for (S,G) entry, it SHALL send out an UNICAST PIM Prune message towards the multicast source. The upstream neighbor address in the message is the source address, and the destination address of the message is that of the source. The UNICAST PIM Prune message is rate-limited. When PIM FHR receives a PIM graft message or IGMP Membership Report and creates a forwarding out interface for the (S,G) entry that had no forwarding out interface before, it SHALL send out an UNICAST PIM Join message towards source immediately. It MAY send some PIM Join messages in a high frequency for reliability. When PIM FHR receives a PIM Prune message or IGMP Leave and deletes the last forwarding out interface for the (S,G) entry, then it SHALL send out UNICAST PIM Prune messages towards source. Only when source address of the multicast stream is in the same network with receiving interface, or when FHR has no RPF neighbour for the (S,G) entry shall FHR send out UNICAST PIM Join or Prune message towards source. Zhou, et al. Expires June 3, 2011 [Page 6] Internet-Draft FHR Source Network Prohibition November 2010 4. Other solutions The UNICAST PIM Join message could be replaced with UNICAST IGMP Graft like message, and the UNICAST PIM Prune message could be also replaced with UNICAST IGMP Prune like message. But some new types of IGMP/MLD messages shall be designed. Zhou, et al. Expires June 3, 2011 [Page 7] Internet-Draft FHR Source Network Prohibition November 2010 5. Security Considerations Zhou, et al. Expires June 3, 2011 [Page 8] Internet-Draft FHR Source Network Prohibition November 2010 6. Contributors Zhou, et al. Expires June 3, 2011 [Page 9] Internet-Draft FHR Source Network Prohibition November 2010 7. Acknowledgements Zhou, et al. Expires June 3, 2011 [Page 10] Internet-Draft FHR Source Network Prohibition November 2010 8. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4541] Christensen, M., Kimball, K., and F. Solensky, "Considerations for Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Snooping Switches", RFC 4541, May 2006. [RFC4601] Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, "Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol Specification (Revised)", RFC 4601, August 2006. Zhou, et al. Expires June 3, 2011 [Page 11] Internet-Draft FHR Source Network Prohibition November 2010 Authors' Addresses Di Zhou (editor) Hangzhou H3C Tech. Co., Ltd. 310 Liuhe Road Hangzhou, Zhejiang China(310053) Phone: +86-571-86761327 Email: zhoudi@h3c.com Hui Deng China Mobile Research Institute Unit2,28 Xuanwumenxi Ave,Xuanwu District Beijing, Beijing China(100053) Phone: +86-010-15801696688-3314 Email: denghui@chinamobile.com Yu Liu Hangzhou H3C Tech. Co., Ltd. Beijing R&D Center of H3C, Digital Technology Plaza, NO.9 Shangdi 9th Street,Haidian District, Beijing China(100085) Phone: +86 010 82775153 Email: liuyu@h3c.com Yang Shi Hangzhou H3C Tech. Co., Ltd. Beijing R&D Center of H3C, Digital Technology Plaza, NO.9 Shangdi 9th Street,Haidian District, Beijing China(100085) Phone: +86 010 82775276 Email: young@h3c.com Zhou, et al. Expires June 3, 2011 [Page 12] Internet-Draft FHR Source Network Prohibition November 2010 Hui Liu Huawei Technologies Co., Ltd. Huawei Bld., No.3 Xinxi Rd. Shang-Di Information Industry Base, Hai-Dian Distinct, Beijing China(100085) Email: helen.liu@huawei.com Indranil Bhattacharya Cisco Systems India(560037) Email: myselfindranil@gmail.com Xiaomin Xu Cisco Systems China(200051) Email: xiaomxu@cisco.com Zhou, et al. Expires June 3, 2011 [Page 13]