Subject: WG Review: Bidirectional Forwarding Detection (bfd)

From: The IESG <[email-masked]>
Date: Tue, 16 Oct 2012 08:11:27 -0700

The Bidirectional Forwarding Detection (bfd) working group in the Routing
Area of the IETF is undergoing rechartering. The IESG has not made any
determination yet. The following draft charter was submitted, and is
provided for informational purposes only. Please send your comments to
the IESG mailing list (iesg at ietf.org) by 2012-10-23.

Bidirectional Forwarding Detection (bfd)
------------------------------------------------
Current Status: Active Working Group

Chairs:
  David Ward <[email-masked]>
  Jeffrey Haas <[email-masked]>

Technical advisors:
  Dave Katz <[email-masked]>

Assigned Area Director:
  Adrian Farrel <[email-masked]>

Mailing list
  Address: [email-masked]
  To Subscribe: [email-masked]
  Archive: http://www.ietf.org/mail-archive/web/rtg-bfd/

Charter of Working Group:

The BFD Working Group is chartered to standardize and support the
bidirectional forwarding detection protocol (BFD) and its extensions.  A
core goal of the working group is to standardize BFD in the context of IP
routing, or protocols such as MPLS that are based on IP routing, in a way
that will encourage multiple, inter-operable vendor implementations.  The
Working Group will also provide advice and guidance on BFD to other
working
groups or standards bodies as requested.

BFD is a protocol intended to detect faults in the bidirectional path
between two forwarding engines, including physical interfaces,
subinterfaces, data link(s), and to the extent possible the forwarding
engines themselves, with potentially very low latency. It operates
independently of media, data protocols, and routing protocols. An
additional goal is to provide a single mechanism that can be used for
liveness detection over any media, at any protocol layer, with
a wide range of detection times and overhead, to avoid a proliferation
of different methods.

Important characteristics of BFD include:

- Simple, fixed-field encoding to facilitate implementations in hardware.

- Independence of the data protocol being forwarded between two systems.
  BFD packets are carried as the payload of whatever encapsulating
protocol
  is appropriate for the medium and network.

- Path independence: BFD can provide failure detection on any kind of
path
  between systems, including direct physical links, virtual circuits,
  tunnels, MPLS LSPs, multihop routed paths, and unidirectional links (so
  long as there is some return path, of course).

- Ability to be bootstrapped by any other protocol that automatically
forms
  peer, neighbor or adjacency relationships to seed BFD endpoint
discovery.

The working group is chartered to complete the following work items:

1. Develop the MIB module for BFD and submit it to the IESG for
publication
as a Proposed Standard.

2a. Provide a generic keying-based cryptographic authentication mechanism
for
the BFD protocol in discussion with the KARP working group.  This
mechanism 
will support authentication through a key identifier for the BFD
session's 
Security Association rather than specifying new authentication
extensions.  

2b. Provide extensions to the BFD MIB in support of the generic
keying-based
cryptographic authentication mechanism.

2c. Specify cryptographic authentication procedures for the BFD protocol
using HMAC-SHA-256 (possibly truncated to a smaller integrity check
value)
using the generic keying-based cryptographic authentication mechanism.

3. Provide an extension to the BFD core protocol in support of point-to-
multipoint links and networks.

4. Assist the MPLS working group in the standardization of the BFD
protocol
for MPLS-TP.  The preferred solution will be interoperable with the
current
BFD specification.

5. Provide one or more mechanisms to run BFD over Link Aggregation Group
Interfaces.

The working group will maintain a relationship with the KARP and MPLS 
working groups, and will communicate with the IEEE with respect to BFD
over LAGs.

Milestones:
  Done     - Submit the base protocol specification to the IESG to be
considered as a Proposed Standard
  Done     - Submit BFD encapsulation and usage profile for single-hop
IPv4 and IPv6 adjacencies to the IESG to be considered as a Proposed
Standard
  Done     - Submit BFD encapsulation and usage profile for MPLS LSPs to
the IESG to be considered as a Proposed Standard
  Done     - Submit BFD encapsulation and usage profile for multi-hop
IPv4 and IPv6 adjacencies to the IESG to be considered as a Proposed
Standard
  Sep 2011 - Submit the BFD MIB to the IESG to be considered as a
Proposed Standard
  Dec 2011 - Submit the generic keying based cryptographic authentication
mechanism to the IESG to be considered as a Proposed Standard
  Dec 2011 - Submit a BFD MIB extension in support of the generic keying
document to the IESG to be considered as a Proposed Standard
  Dec 2011 - Submit the cryptographic authentication procedures for BFD
to the IESG to be considered as a Proposed Standard
  Mar 2012 - Submit the the document on BFD point-to-multipoint support
to the IESG to be considered as a Proposed Standard
  Jun 2012 - Submit the bootstrapping mechanism for BFD using DHCP to the
IESG to be considered as a Proposed Standard