Network Working Group V. Kamath Internet-Draft VMware Intended status: Standards Track R. Chokkanathapuram Sundaram Expires: October 14, 2019 R. Banthia Cisco Systems, Inc. April 12, 2019 PIM Null register packing draft-ramki-pim-null-register-packing-03 Abstract In PIM-SM networks PIM registers are sent from the first hop router to the RP (Rendezvous Point) to signal the presence of Multicast source in the network. There are periodic PIM Null registers sent from first hop router to the RP to keep the state alive at the RP as long as the source is active. The PIM Null register packet carries information about a single Multicast source and group. This document defines a standard to send multiple Multicast source and group information in a single pim Null register packet and the interoperability between the PIM routers which do not understand the packet format with multiple Multicast source and group details. 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 https://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 October 14, 2019. Copyright Notice Copyright (c) 2019 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 Kamath, et al. Expires October 14, 2019 [Page 1] Internet-Draft PIM Null register packing April 2019 (https://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. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Conventions Used in This Document . . . . . . . . . . . . 2 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. PIM Register Stop format with capability option . . . . . . . 3 3. New PIM Null register message . . . . . . . . . . . . . . . . 4 4. New PIM Register Stop message format . . . . . . . . . . . . 4 5. Protocol operation . . . . . . . . . . . . . . . . . . . . . 5 6. PIM Anycast RP considerations . . . . . . . . . . . . . . . . 6 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 9.2. Informative References . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction PIM Null registers are sent by First hop routers periodically for Multicast streams to keep the states active on the RP as long as the Multicast source is alive. As the number of multicast sources increases, the number of PIM Null register packets that are sent increases at a given time. This results in more PIM packet processing at RP and FHR. The control plane policing (COPP), monitors the packets that gets processed by the control plane. Due to the high rate at which Null registers are received at the RP, this can lead to COPP drops of Multicast PIM Null register packets. This draft proposes a method to efficiently pack multiple PIM Null registers and register stop into a single message as these packets anyway don't contain data. The draft also proposes interoperability with the routers that do not understand the new packet format. 1.1. Conventions Used in This Document 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]. Kamath, et al. Expires October 14, 2019 [Page 2] Internet-Draft PIM Null register packing April 2019 1.2. 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 2. PIM Register Stop format with capability option A router (FHR) can decide to pack multiple Null registers based on the capability received from the RP as part of Register Stop. This ensures compatibility with routers that don't support processing of the new format. The capability information can be indicated by the RP via the PIM register stop message sent to the FHR. Thus a FHR will switch to the new format only when it learns RP is capable of handling the packed Null register messages. Conversely, a FHR that doesn't support the new format can continue generating the PIM Null register the current way. To exchange the capability information in the Register Stop message, the "reserved" field can be used to indicate this capability in those register stop messages. One bit of the reserved field is used to indicate the "packing" capability (P bit). The rest of the bits in the "Reserved" field will be retained for future use. Figure 1: PIM Register Stop message with capability option 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |PIM Ver| Type |P| Reserved | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Group Address (Encoded-Group format) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Address (Encoded-Unicast format) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ PIM Version, Reserved, Type, Checksum, Group Address, Source Address Same as RFC 7761 (Section 4.9.4) P Capability bit used to indicate support for Packed Null Register Kamath, et al. Expires October 14, 2019 [Page 3] Internet-Draft PIM Null register packing April 2019 3. New PIM Null register message New PIM Null register message format includes a count to indicate the number of Null register records in the message. Figure 2: New PIM Null Register message format 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |PIM Ver| Type |SubType| Rsvd | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | count | Reserved2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Group Address[1] (Encoded-Group format) | | Source Address[1] (Encoded-Unicast format) | . . . . . . . . . Group Address[N] . | Source Address[N] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ PIM Version, Reserved, Checksum Same as RFC 7761 (Section 4.9.3) Type, SubType The new packed Null Register Type and SubType values TBD count The count of the number of packed Null register records. A record consists of Group and Source Address Group Address IP address of the Multicast Group Source Address IP Address of the Multicast Source 4. New PIM Register Stop message format The new PIM register stop is message includes a count to indicate the number of records that are present in the message. Kamath, et al. Expires October 14, 2019 [Page 4] Internet-Draft PIM Null register packing April 2019 Figure 3: New PIM Register Stop message format 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |PIM Ver| Type |SubType| Rsvd | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | count | Reserved2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Group Address[1] (Encoded-Group format) | | Source Address[1] (Encoded-Unicast format) | . . . . . . . . . Group Address[N] . | Source Address[N] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ PIM Version, Reserved, Checksum Same as RFC 7761 (Section 4.9.3) Type The new Register Stop Type and SubType values TBD Record count The count of the number of packed register stop records. A record consists of Group and Source Address Group Address IP address of the Multicast Group Source Address IP Address of the Multicast Source 5. Protocol operation Kamath, et al. Expires October 14, 2019 [Page 5] Internet-Draft PIM Null register packing April 2019 The following combinations exist - FHR and RP both support the new PIM Register formats - a. FHR sends the PIM register towards the RP when a new source is detected b. RP sends a modified register stop towards the FHR that includes capability information by setting the P bit (Figure 2) c. Based on the receipt of new Register Stop, FHR will start packing of Null registers using the new packed register format (Figure 1) d. RP processes the new Null register message and can generate new register Stop messages by packing multiple S,Gs towards the same FHR (Figure 3) FHR supports but RP doesn't support new PIM Register formats- a. FHR sends the PIM register towards the RP b. RP sends a normal register stop without any capability information c. FHR then sends Null registers in the old format RP supports but FHR doesn't support the new PIM Register formats- a. FHR sends the PIM register towards the RP b. RP sends a modified register stop towards the FHR that includes capability information c. Since FHR doesn't support the new format, it sends Null registers in the old format 6. PIM Anycast RP considerations The new PIM register format should be enabled only if its supported by all PIM anycast RP members in the RP set for the RP address. 7. IANA Considerations This document requires the assignment of 2 new PIM message types for the packed pim register and pim register stop. 8. Acknowledgments The authors would like to thank Stig Venaas and Umesh Dudani for contributing to the original idea and also their very helpful comments on the draft. 9. References Kamath, et al. Expires October 14, 2019 [Page 6] Internet-Draft PIM Null register packing April 2019 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . 9.2. Informative References [RFC3973] Adams, A., Nicholas, J., and W. Siadak, "Protocol Independent Multicast - Dense Mode (PIM-DM): Protocol Specification (Revised)", RFC 3973, DOI 10.17487/RFC3973, January 2005, . Authors' Addresses Vikas Ramesh Kamath VMware 3401 Hillview Ave Palo Alto CA 94304 USA Email: vkamath@vmware.com Ramakrishnan Chokkanathapuram Sundaram Cisco Systems, Inc. Tasman Drive San Jose CA 95134 USA Email: ramaksun@cisco.com Raunak Banthia Cisco Systems, Inc. Tasman Drive San Jose CA 95134 USA Email: rbanthia@cisco.com Kamath, et al. Expires October 14, 2019 [Page 7]