Bidirectional Forwarding Detection
|Document||Charter||Bidirectional Forwarding Detection WG (bfd) Snapshot|
|Title||Bidirectional Forwarding Detection|
|IESG||Responsible AD||John Scudder|
|Charter edit AD||John Scudder|
|Send notices to||(None)|
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 currently chartered to complete the following work items: 1. Develop further MIB modules for BFD and submit them to the IESG for publication as Proposed Standards. 2a. Provide a generic keying-based cryptographic authentication mechanism for the BFD protocol developing the work of 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 but not beyond commonly accepted lengths to ensure security) 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. Provide an informational document to recommend standardized timers and timer operations for BFD when used in different applications. 5. Define a mechanism to perform single-ended path (i.e. continuity) verification based on the BFD specification. Allow such a mechanism to work both proactively and on-demand, without prominent initial delay. Allow the mechanism to maintain multiple sessions to a target entity and between the same pair of network entities. In doing this work, the WG will work closely with at least the following other WGs: ISIS, OSPF, SPRING. The working group will maintain a relationship with the MPLS working group.