< draft-ietf-rtgwg-vrrp-p2mp-bfd-01.txt   draft-ietf-rtgwg-vrrp-p2mp-bfd-02.txt >
BFD Working Group G. Mirsky BFD Working Group G. Mirsky
Internet-Draft Ericsson Internet-Draft Ericsson
Updates: 5798 (if approved) J. Tantsura Updates: 5798 (if approved) J. Tantsura
Intended status: Standards Track Microsoft Intended status: Standards Track Microsoft
Expires: 22 September 2022 G. Mishra Expires: 2 October 2022 G. Mishra
Verizon Inc. Verizon Inc.
21 March 2022 31 March 2022
Applicability of Bidirectional Forwarding Detection (BFD) for Multi- Applicability of Bidirectional Forwarding Detection (BFD) for Multi-
point Networks in Virtual Router Redundancy Protocol (VRRP) point Networks in Virtual Router Redundancy Protocol (VRRP)
draft-ietf-rtgwg-vrrp-p2mp-bfd-01 draft-ietf-rtgwg-vrrp-p2mp-bfd-02
Abstract Abstract
This document discusses the applicability of Bidirectional Forwarding This document discusses the applicability of Bidirectional Forwarding
Detection (BFD) for multipoint networks to provide Virtual Router Detection (BFD) for multipoint networks to provide Virtual Router
Redundancy Protocol (VRRP) with sub-second Active convergence and Redundancy Protocol (VRRP) with sub-second convergence of the Active
defines the extension to bootstrap point-to-multipoint BFD session. router and defines the extension to bootstrap point-to-multipoint BFD
session.
This draft updates RFC 5798. This draft updates RFC 5798.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 22 September 2022. This Internet-Draft will expire on 2 October 2022.
Copyright Notice Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the Copyright (c) 2022 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 3 1.1. Conventions used in this document . . . . . . . . . . . . 2
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3 2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
3. Applicability of p2mp BFD . . . . . . . . . . . . . . . . . . 3 3. Applicability of p2mp BFD . . . . . . . . . . . . . . . . . . 3
3.1. Multipoint BFD Encapsulation . . . . . . . . . . . . . . 5 3.1. Multipoint BFD Encapsulation . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. Normative References . . . . . . . . . . . . . . . . . . . . 5 7. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
skipping to change at page 2, line 42 skipping to change at page 2, line 44
Bidirectional Forwarding Detection (BFD) [RFC5880] had been Bidirectional Forwarding Detection (BFD) [RFC5880] had been
originally defined detect failure of point-to-point (p2p) paths: originally defined detect failure of point-to-point (p2p) paths:
single-hop [RFC5881], multihop [RFC5883]. Single-hop BFD may be used single-hop [RFC5881], multihop [RFC5883]. Single-hop BFD may be used
to enable Backup routers to detect a failure of the Active router to enable Backup routers to detect a failure of the Active router
within 100 msec or faster. within 100 msec or faster.
[RFC8562] extends [RFC5880] for multipoint and multicast networks, [RFC8562] extends [RFC5880] for multipoint and multicast networks,
which matches the deployment scenarios for VRRP over the LAN segment. which matches the deployment scenarios for VRRP over the LAN segment.
This document demonstrates how point-to-multipoint (p2mp) BFD can This document demonstrates how point-to-multipoint (p2mp) BFD can
enable faster detection of Active failure and thus minimize service enable faster detection of the Active router failure and thus
disruption in a VRRP domain. The document also defines the extension minimize service disruption in a VRRP domain. The document also
to VRRP [RFC5798] to bootstrap a VRRP Backup router to join in p2mp defines the extension to VRRP [RFC5798] to bootstrap a VRRP Backup
BFD session. router to join in a p2mp BFD session.
1.1. Conventions used in this document 1.1. Conventions used in this document
1.1.1. Terminology 1.1.1. Terminology
BFD: Bidirectional Forwarding Detection BFD: Bidirectional Forwarding Detection
p2mp: Pont-to-Multipoint p2mp: Pont-to-Multipoint
VRRP: Virtual Router Redundancy Protocol VRRP: Virtual Router Redundancy Protocol
1.1.2. Requirements Language 1.1.2. Requirements Language
skipping to change at page 3, line 37 skipping to change at page 3, line 34
for VRRPv3 [RFC5798] for all these roles without specialized support for VRRPv3 [RFC5798] for all these roles without specialized support
in the data plane may prove challenging. BFD already has many in the data plane may prove challenging. BFD already has many
implementations based on HW that are capable of supporting multiple implementations based on HW that are capable of supporting multiple
sub-second sessions concurrently. sub-second sessions concurrently.
3. Applicability of p2mp BFD 3. Applicability of p2mp BFD
[RFC8562] may provide an efficient and scalable solution for fast- [RFC8562] may provide an efficient and scalable solution for fast-
converging environment that uses the default route rather than converging environment that uses the default route rather than
dynamic routing. Each redundancy group presents itself as a p2mp BFD dynamic routing. Each redundancy group presents itself as a p2mp BFD
session, with its Active being the root and Backup routers being the session, with its Active router being the root and Backup routers
tails of the p2mp BFD session. Figure 1 displays the extension of being the tails of the p2mp BFD session. Figure 1 displays the
VRRP [RFC5798] to bootstrap a tail of the p2mp BFD session. extension of VRRP [RFC5798] to bootstrap a tail of the p2mp BFD
session.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr| |Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Rsvd |B| Max Adver Int | Checksum | |Rsvd |B| Max Adver Int | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ + + +
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value of My Discriminator MUST be set as the value of the Active value of My Discriminator MUST be set as the value of the Active
Router Discriminator field. The BFD flag MUST be set in the VRRP Router Discriminator field. The BFD flag MUST be set in the VRRP
packet. A Backup router demultiplexes p2mp BFD test sessions based packet. A Backup router demultiplexes p2mp BFD test sessions based
on VRID that it has been configured with and the non-zero My on VRID that it has been configured with and the non-zero My
Discriminator value it learns from the received VRRP packet. When a Discriminator value it learns from the received VRRP packet. When a
Backup router detects the failure of the Active router, it re- Backup router detects the failure of the Active router, it re-
evaluates its role in the VRID. As a result, the Backup router may evaluates its role in the VRID. As a result, the Backup router may
become the Active router of the given VRID or continue as a Backup become the Active router of the given VRID or continue as a Backup
router. If the former is the case, then the new Active router MUST router. If the former is the case, then the new Active router MUST
select My Discriminator and start transmitting p2mp BFD control select My Discriminator and start transmitting p2mp BFD control
packets using Active IP address as the source IP address for p2mp BFD packets using Active router IP address as the source IP address for
control packets. If the latter is the case, then the Backup router p2mp BFD control packets. If the latter is the case, then the Backup
MUST wait for the VRRP packet from the new VRRP Active router that router MUST wait for the VRRP packet from the new VRRP Active router
will bootstrap the new p2mp BFD session. that will bootstrap the new p2mp BFD session.
3.1. Multipoint BFD Encapsulation 3.1. Multipoint BFD Encapsulation
The MultipointHead of p2mp BFD session when transmitting BFD control The MultipointHead of p2mp BFD session when transmitting BFD control
packet: packet:
MUST set TTL or Hop Limit value to 255 (Section 5 [RFC5881]). MUST set TTL or Hop Limit value to 255 (Section 5 [RFC5881]).
Similarly, all received BFD Control packets that are demultiplexed Similarly, all received BFD Control packets that are demultiplexed
to the session MUST be discarded if the received TTL or Hop Limit to the session MUST be discarded if the received TTL or Hop Limit
is not equal to 255; is not equal to 255;
SHOULD use group address VRRP ('224.0.0.18' for IPv4 and SHOULD use group address VRRP ('224.0.0.18' for IPv4 and
'FF02:0:0:0:0:0:0:12' for IPv6) as destination IP address 'FF02:0:0:0:0:0:0:12' for IPv6) as destination IP address
MAY use network broadcast address for IPv4 or link-local all nodes MAY use network broadcast address for IPv4 or link-local all nodes
multicast group for IPv6 as destination IP address; multicast group for IPv6 as destination IP address;
MUST set destination UDP port value to 3784 when transmitting BFD MUST set destination UDP port value to 3784 when transmitting BFD
control packets, as defined in [RFC8562]; control packets, as defined in [RFC8562];
MUST use the Active IP address as the source IP address. MUST use the Active router IP address as the source IP address.
4. IANA Considerations 4. IANA Considerations
This document makes no requests for IANA allocations. This section This document makes no requests for IANA allocations. This section
may be deleted by RFC Editor. may be deleted by RFC Editor.
5. Security Considerations 5. Security Considerations
This document defines an alternative way, to the one defined in This document defines an alternative way, to the one defined in
[RFC5798], to accelerate detecting a failure that affects VRRP [RFC5798], to accelerate detecting a failure that affects VRRP
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