PIM WG Stig. Venaas Internet-Draft Cisco Systems, Inc. Intended status: Standards Track Zheng. Zhang Expires: January 8, 2017 ZTE Corporation July 7, 2016 PIM IGP EXT draft-zhang-pim-igp-ext-01 Abstract This document introduces a method to advertise multicast source information. The information will be flooded all over the network by OSPF, ISIS and Babel extension. This allows PIM Sparse Mode routers with connected receivers to build a Shortest Path Tree straight away, with no need for a shared a tree. 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 January 8, 2017. 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 Venaas & Zhang Expires January 8, 2017 [Page 1] Internet-Draft PIM IGP EXT July 2016 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Advertisement mechanism . . . . . . . . . . . . . . . . . . . 3 4. IGP extension . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. OSPF extension . . . . . . . . . . . . . . . . . . . . . 3 4.2. ISIS extension . . . . . . . . . . . . . . . . . . . . . 4 4.3. Babel extension . . . . . . . . . . . . . . . . . . . . . 4 5. Security Consideration . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 7. Normative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Terminology RP: Rendezvous Point. RPF: Reverse Path Forwarding. SPT: Shortest Path Tree. FHR: First Hop Router, directly connected to the source. LHR: Last Hop Router, directly connected to the receiver. SG Mapping: Multicast source to group mapping. MSGI: Multicast Source and group Information as abbreviation. 2. Introduction [RFC4601] and [RFC7761] introduces that RP can be used to collect the receiver and source information. Obviously, RP may be bottleneck in some busy network. Though the RP-mapping mechanism [RFC6226] is used to make different RP in charge of different groups, it makes the network management more difficult and complex. [I-D.ietf-pim-source-discovery-bsr] defines an effective way to deliver multicast information by the way of PIM packet flooding. This function is very useful in network with the routers that are all credible and controllable. Some routers may be attacked or forged in some networks. In these networks, the source information announcement may be forged. There Venaas & Zhang Expires January 8, 2017 [Page 2] Internet-Draft PIM IGP EXT July 2016 is authentication method in IGP advertisement, such as OSPF, ISIS and Babel. Authentication can prevent a router from injecting messages with non-existing multicast sources. So the source information announcement may be carried in OSPF, ISIS and Babel extension. 3. Advertisement mechanism OSPF and ISIS are deployed widely in internet. And the two protocols are the most popular and important routing protocol. The flooding feature is an effective way to advertise the change of network topology. In order to advertise the MSGI, the IGP flooding feature is beneficial to spread the information to PIM routers that have, or potentially may have, connected receivers. Babel [RFC6126] is a loop-avoiding distance-vector routing protocol that is robust and efficient both in ordinary wired networks and in wireless mesh networks. And multicast service is useful in wired networks and wireless networks. [RFC7298] defines the authentication method of Babel. Babel extension can be used to delivery MSGI. When a router starts receiving packets from a directly connected source, it should advertise a MSGI for the source in the IGP, and keep doing so as long as the source is active. Along with the IGP flooding, the MSGI will quickly spread all over the network. All routers receive the advertisement of the MSGI after flooding. A router that is a LHR, joins the SPT towards the announced source according to standard PIM Sparse Mode procedures, by sending a join to the RPF neighbor towards the source. Routers that do not have any connected receivers store the MSGI, such that they can immediately join the SPT if they later should become a LHR. 4. IGP extension 4.1. OSPF extension A new type of the OSPF Opaque LSA is defined for OSPF MSGI capability. And the same for OSPFv2 and OSPFv3. The format is: Venaas & Zhang Expires January 8, 2017 [Page 3] Internet-Draft PIM IGP EXT July 2016 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Group Address (Encoded-Group format) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Src Address (Encoded-Unicast format) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type : The value is TBD. 12 or later digit can be used. o Length: The length of the value. o Group Address: The group we are announcing sources for. The format for this address is given in the Encoded-Group format in [RFC7761]. o Src Address: The source address for the corresponding group. The format for these addresses is given in the Encoded-Unicast address in [RFC7761]. The TLV repeats for many groups and groups. In the case where a source stops sending, the FHR simply stops announcing the TLVs. Then the other routers delete the source information. 4.2. ISIS extension A new ISIS TLV is defined for the MSGI advertisement. The format of the TLV is same as OSPF. 4.3. Babel extension A new Babel TLV is defined for MSGI advertisement according to [RFC7557]. The format is same as OSPF. 5. Security Consideration OSPF and ISIS protocol have the capability of authentication. The security function can be used unchanged for the MSGI advertisement. The authentication method defined in Babel [RFC7298] can be used unchanged for MSGI advertisement. Venaas & Zhang Expires January 8, 2017 [Page 4] Internet-Draft PIM IGP EXT July 2016 6. IANA Considerations A new OSPF Opaque LSA need to be added for carrying OSPF MSGI TLV. A new MSGI TLV need to be added for ISIS MSGI advertisement. A new Babel TLV is defined for MSGI advertisement according to [RFC7557]. 7. Normative References [I-D.ietf-pim-source-discovery-bsr] Wijnands, I., Venaas, S., Brig, M., and A. Jonasson, "PIM flooding mechanism and source discovery", draft-ietf-pim- source-discovery-bsr-04 (work in progress), March 2016. [RFC4601] Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, "Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol Specification (Revised)", RFC 4601, DOI 10.17487/RFC4601, August 2006, . [RFC6126] Chroboczek, J., "The Babel Routing Protocol", RFC 6126, DOI 10.17487/RFC6126, April 2011, . [RFC6226] Joshi, B., Kessler, A., and D. McWalter, "PIM Group-to- Rendezvous-Point Mapping", RFC 6226, DOI 10.17487/RFC6226, May 2011, . [RFC7298] Ovsienko, D., "Babel Hashed Message Authentication Code (HMAC) Cryptographic Authentication", RFC 7298, DOI 10.17487/RFC7298, July 2014, . [RFC7557] Chroboczek, J., "Extension Mechanism for the Babel Routing Protocol", RFC 7557, DOI 10.17487/RFC7557, May 2015, . [RFC7761] Fenner, B., Handley, M., Holbrook, H., Kouvelas, I., Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol Specification (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March 2016, . Venaas & Zhang Expires January 8, 2017 [Page 5] Internet-Draft PIM IGP EXT July 2016 [RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, February 2016, . Authors' Addresses Stig Venaas Cisco Systems, Inc. Tasman Drive San Jose CA 95134 USA Email: stig@cisco.com Zheng(Sandy) Zhang ZTE Corporation No. 50 Software Ave, Yuhuatai Distinct Nanjing China Email: zhang.zheng@zte.com.cn Venaas & Zhang Expires January 8, 2017 [Page 6]