PIM Designated Router Load Balancing
RFC 8775
Document | Type |
RFC - Proposed Standard
(April 2020; No errata)
Was draft-ietf-pim-drlb (pim WG)
|
|
---|---|---|---|
Authors | Yiqun Cai , Heidi Ou , Sri Vallepalli , Mankamana Mishra , Stig Venaas , Andy Green | ||
Last updated | 2020-04-22 | ||
Replaces | draft-hou-pim-drlb | ||
Stream | IETF | ||
Formats | plain text html xml pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Mike McBride | ||
Shepherd write-up | Show (last changed 2019-01-14) | ||
IESG | IESG state | RFC 8775 (Proposed Standard) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Alvaro Retana | ||
Send notices to | aretana.ietf@gmail.com | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) Y. Cai Request for Comments: 8775 H. Ou Category: Standards Track Alibaba Group ISSN: 2070-1721 S. Vallepalli M. Mishra S. Venaas Cisco Systems, Inc. A. Green British Telecom April 2020 PIM Designated Router Load Balancing Abstract On a multi-access network, one of the PIM-SM (PIM Sparse Mode) routers is elected as a Designated Router. One of the responsibilities of the Designated Router is to track local multicast listeners and forward data to these listeners if the group is operating in PIM-SM. This document specifies a modification to the PIM-SM protocol that allows more than one of the PIM-SM routers to take on this responsibility so that the forwarding load can be distributed among multiple routers. 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 https://www.rfc-editor.org/info/rfc8775. Copyright Notice Copyright (c) 2020 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 (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. Terminology 3. Applicability 4. Functional Overview 4.1. GDR Candidates 5. Protocol Specification 5.1. Hash Mask and Hash Algorithm 5.2. Modulo Hash Algorithm 5.2.1. Modulo Hash Algorithm Examples 5.2.2. Limitations 5.3. PIM Hello Options 5.3.1. PIM DR Load-Balancing Capability (DRLB-Cap) Hello Option 5.3.2. PIM DR Load-Balancing List (DRLB-List) Hello Option 5.4. PIM DR Operation 5.5. PIM GDR Candidate Operation 5.6. DRLB-List Hello Option Processing 5.7. PIM Assert Modification 5.8. Backward Compatibility 6. Operational Considerations 7. IANA Considerations 7.1. Initial Registry 7.2. Assignment of New Hash Algorithms 8. Security Considerations 9. References 9.1. Normative References 9.2. Informative References Acknowledgements Authors' Addresses 1. Introduction On a multi-access LAN (such as an Ethernet) with one or more PIM-SM (PIM Sparse Mode) [RFC7761] routers, one of the PIM-SM routers is elected as a Designated Router (DR). The PIM DR has two responsibilities in the PIM-SM protocol. For any active sources on a LAN, the PIM DR is responsible for registering with the Rendezvous Point (RP) if the group is operating in PIM-SM. Also, the PIM DR is responsible for tracking local multicast listeners and forwarding data to these listeners if the group is operating in PIM-SM. Consider the following LAN in Figure 1: (core networks) | | | | | | R1 R2 R3 | | | ----(LAN)---- | | (many receivers) Figure 1: LAN with Receivers Assume R1 is elected as the DR. According to the PIM-SM protocol, R1 will be responsible for forwarding traffic to that LAN on behalf of all local members. In addition to keeping track of membership reports, R1 is also responsible for initiating the creation of source and/or shared trees towards the senders or the RPs. The membershipShow full document text