--- 1/draft-ietf-pim-drlb-09.txt 2018-11-13 10:13:14.603104232 -0800 +++ 2/draft-ietf-pim-drlb-10.txt 2018-11-13 10:13:14.643105177 -0800 @@ -1,24 +1,24 @@ Network Working Group Y. Cai Internet-Draft H. Ou Intended status: Standards Track Alibaba Group -Expires: April 25, 2019 S. Vallepalli +Expires: May 17, 2019 S. Vallepalli M. Mishra S. Venaas Cisco Systems, Inc. A. Green British Telecom - October 22, 2018 + November 13, 2018 PIM Designated Router Load Balancing - draft-ietf-pim-drlb-09 + draft-ietf-pim-drlb-10 Abstract On a multi-access network, one of the PIM routers is elected as a Designated Router (DR). On the last hop LAN, the PIM DR is responsible for tracking local multicast listeners and forwarding traffic 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 these last hop routers to be selected, so that the forwarding load can be distributed among these routers. @@ -31,21 +31,21 @@ 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 April 25, 2019. + This Internet-Draft will expire on May 17, 2019. Copyright Notice Copyright (c) 2018 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 @@ -72,21 +72,21 @@ 6. Protocol Specification . . . . . . . . . . . . . . . . . . . 11 6.1. PIM DR Operation . . . . . . . . . . . . . . . . . . . . 11 6.2. PIM GDR Candidate Operation . . . . . . . . . . . . . . . 12 6.2.1. Router Receives New DRLBGDR . . . . . . . . . . . . . 13 6.2.2. Router Receives Updated DRLBGDR . . . . . . . . . . . 13 6.3. PIM Assert Modification . . . . . . . . . . . . . . . . . 14 7. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 15 8. Manageability Considerations . . . . . . . . . . . . . . . . 16 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 9.1. Initial registry . . . . . . . . . . . . . . . . . . . . 16 - 9.2. Assignment of new message types . . . . . . . . . . . . . 16 + 9.2. Assignment of new hash algorithms . . . . . . . . . . . . 16 10. Security Considerations . . . . . . . . . . . . . . . . . . . 16 11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 17 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 17 12.1. Normative References . . . . . . . . . . . . . . . . . . 17 12.2. Informative References . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction On a multi-access LAN such as an Ethernet, one of the PIM routers is @@ -315,27 +315,26 @@ o If the group is in ASM mode and the RP Hash Mask announced by the PIM DR is 0, obtain the value of hashvalue_Group [Section 4.3 ] to determine GDR. o If the group is in SSM mode, use hashvalue_SG [Section 4.3] to determine GDR. A simple Modulo hash algorithm is defined in this document. However, to allow another hash algorithms to be used, a 1-octet "Hash - Algorithm Type" field is included in DRLBC Hello Option to specify - the hash algorithm used by a last hop router. + Algorithm" field is included in DRLBC Hello Option to specify the + hash algorithm used by a last hop router. - If different hash algorithm types are advertised among last hop - routers, only last hop routers running the same hash algorithm as the - DR (and having the same DR priority as the DR) are eligible for GDR - election. + If different hash algorithms are advertised among last hop routers, + only last hop routers running the same hash algorithm as the DR (and + having the same DR priority as the DR) are eligible for GDR election. 4.3. Modulo Hash Algorithm The Modulo hash algorithm is discussed here with a detailed description on hashvalue_RP. The same algorithm is described in brief for hashvalue_Group using the group address instead of the RP address for an ASM group with zero RP_hashmask, and also with hashvalue_SG for a the source address of an (S,G), instead of the RP address, @@ -419,30 +417,30 @@ 5. Hello Option Formats 5.1. PIM DR Load Balancing Capability (DRLBC) Hello 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = TBD | Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Reserved | Hash Type | + | Reserved |Hash Algorithm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Capability Hello Option Type: TBD Length: 4 - Hash Algorithm Type: 0 for Modulo hash algorithm + Hash Algorithm: 0 for Modulo This DRLBC Hello Option MUST be advertised by last hop routers on interfaces with this specification enabled. 5.2. PIM DR Load Balancing GDR (DRLBGDR) Hello 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = TBD | Length | @@ -512,22 +510,22 @@ configuration, followed by a sorted list of GDR Candidate Addresses, from the highest value to the lowest value. Moreover, same as non-DR routers, the DR also advertises DRLBC Hello Option to indicate its capability of supporting this specification and the type of its GDR election hash algorithm. If a PIM DR receives a PIM Hello with the DRLBGDR Option, the PIM DR SHOULD ignore the TLV. If a PIM DR receives a neighbor DRLBC Hello Option, which contains - the same hash algorithm type as the DR, and the neighbor has the same - DR priority as the DR, PIM DR SHOULD consider the neighbor as a GDR + the same hash algorithm as the DR, and the neighbor has the same DR + priority as the DR, PIM DR SHOULD consider the neighbor as a GDR Candidate and insert the GDR Candidate's Address into the sorted list of the DRLBGDR Option. However, the DR MAY have policies limiting which GDR Candidates, or the number of GDR Candidates to include. 6.2. PIM GDR Candidate Operation When an IGMP/MLD report is received, without this specification, only the PIM DR will handle the join and potentially run into the issues described earlier. Using this specification, a hash algorithm is used by the GDR Candidates to determine which router is going to be @@ -701,46 +699,49 @@ o If a router which does not support this specification becomes a non-DR on link, then it acts as non-DR defined in [RFC7761], and it will not take part in any load-balancing. 8. Manageability Considerations Only the routers announcing the same Hash Algorithm as the DR would be considered as GDR candidates. Network administrators need to make sure that the desired set of routers announce the same algorithm. - Migration between different algorithm types is not considered in this + Migration between different algorithms is not considered in this document. 9. IANA Considerations IANA has temporarily assigned type 34 for the PIM DR Load Balancing Capability (DRLBC) Hello Option, and type 35 for the PIM DR Load - Balancing GDR (DRLBGDR) Hello Option. IANA is requested to make - these assignments permanent when this document is published as an - RFC. The string TBD should be replaced by the assigned values - accordingly. This document requests IANA to create a DRLB hash type - registry. This should be placed in the "Protocol Independent - Multicast (PIM)" branch of the tree. + Balancing GDR (DRLBGDR) Hello Option in the PIM-Hello Options + registry. IANA is requested to make these assignments permanent when + this document is published as an RFC. The string TBD should be + replaced by the assigned values accordingly. + + This document requests IANA to create a registry called "Designated + Router Load Balancing Hash Algorithms" in the "Protocol Independent + Multicast (PIM)" branch of the registry tree. The registry lists + hash algorithms for use by PIM Designated Router Load Balancing. 9.1. Initial registry The initial content of the registry should be as follows. Type Name Reference ------ ---------------------------------------- -------------------- - 0 Hash algorithm modulo This document + 0 Modulo This document 1-255 Unassigned -9.2. Assignment of new message types +9.2. Assignment of new hash algorithms - Assignment of new message types is done according to the "IETF + Assignment of new hash algorithms is done according to the "IETF Review" model, see [RFC5226]. 10. Security Considerations Security of the new DR Load Balancing PIM Hello Options is only guaranteed by the security of PIM Hello messages, so the security considerations for PIM Hello messages as described in PIM-SM [RFC7761] apply here. 11. Acknowledgement