Re: Implementation/Conformance Poll for rfc5880 (draft-ietf-bfd-rfc5880bis)

[Mahesh Jethanandani <[e-mail]>]

HI Alvaro,

Here is the implementation/conformance report for RFC 5880 from Arrcus’ perspective.

----------------------------------------

Version: ArcOS 8.1.2

Maturity: Production

§6.3 — Unique discriminator per session: YES. Local and remote discriminators are allocated per session and exposed in operational state.

§6.4 — Echo function: NO. 

§6.5 — Poll sequence: YES. Poll sequences are used internally when BFD session parameters change mid-session (timer renegotiation occurs without session teardown). There is no operator-visible poll sequence control.

§6.6 — Demand mode: NO. 

§6.7.2 — Simple password authentication: NO.

§6.7.3 — Keyed MD5 / Meticulous Keyed MD5: NO.

§6.7.4 — Keyed SHA1 / Meticulous Keyed SHA1: NO.

§6.8.1 — State variables:

Variable	Supported
bfd.SessionState	YES
bfd.RemoteSessionState	YES
bfd.LocalDiscr	YES
bfd.RemoteDiscr	YES
bfd.LocalDiag	UNKNOWN — maintained internally but not exposed via CLI; requires confirmation
bfd.DesiredMinTxInterval	YES
bfd.RequiredMinRxInterval	YES
bfd.RemoteMinRxInterval	YES
bfd.DemandMode	NO
bfd.RemoteDemandMode	NO
bfd.DetectMult	YES
bfd.AuthType	NO
bfd.RcvAuthSeq	NO
bfd.XmitAuthSeq	NO
bfd.AuthSeqKnown	NO

§6.8.2 — Timer negotiation: YES. Advertised TX interval = max(DesiredMinTxInterval, peer's RequiredMinRxInterval).

§6.8.3 — Timer manipulation: YES. Timer changes on established sessions are performed in-place without session teardown.

§6.8.4 — Detection time calculation: YES. Detection time = negotiated TX interval × DetectMult.

§6.8.5 — Echo function failure detection: NO.

§6.8.6 — Reception of BFD Control packets: YES.

§6.8.7 — Transmitting BFD Control packets: YES. Both CPU-path and hardware-offloaded transmission are supported.

§6.8.8 — Reception of BFD Echo packets: NO.

§6.8.9 — Transmission of BFD Echo packets: NO.

§6.8.10 — Changing transmit interval: YES.

§6.8.11 — Changing DetectMult: YES.

§6.8.12 — Changing desired min Echo Rx interval: NO.

§6.8.13 — Enabling/disabling Echo function: NO.

§6.8.14 — Enabling/disabling Demand mode: NO.

§6.8.15 — Forwarding plane reset: YES. BFD sessions recover correctly across process restart and hardware offload resync.

§6.8.16 — Administrative control: YES. Per-profile administrative enable/disable (AdminDown state).

§6.8.17 — Concatenated paths: UNKNOWN — multi-hop BFD over single and ECMP paths is supported, but explicit §6.8.17 signaling behavior has not been verified; confirming separately.

§6.8.18 — Session hold down: PARTIAL. BGP sessions can be held down while BFD is down ("strict" mode), but full §6.8.18 semantics have not been explicitly verified.

§9 — Generalized TTL Security Mechanism (GTSM): UNKNOWN — not documented in the current release; confirming with engineering.

Implementation notes:

ArcOS supports hardware-accelerated BFD with offload to Broadcom XGS and DNX ASICs (V4 and V6 independently configurable). Minimum detection intervals in the sub-100ms range are achievable. BFD sessions are supported for BGP, IS-IS, and OSPF clients, with multiple client protocols able to share a single session between the same address pair. Micro BFD for LAG (RFC 7130) and multi-hop BFD (RFC 5883) are also supported.

We plan to address authentication in a future release.

Regards,

> On Jun 19, 2026, at 1:04 PM, Alvaro Retana <[e-mail]> wrote:
> 
> Hi!
> 
> This email starts an implementation/conformance poll for rfc5880.
> 
> Please consider the information requested below and reply to this poll with data about your implementation. You can do it in one of the following ways:
> 
> (1) Reply to this message.
> 
> (2) Fill out this form: https://forms.gle/M5ss7weaYebwjhRy5 
> 
> (3) Submit a PR in GitHub; here's a template: https://github.com/bfd-wg/draft-ietf-bfd-rfc5880-bis/blob/main/rfc5880_Conformance.xml 
> 
> Thanks!
> 
> Alvaro.
> 
> 
> # Required Information
> 
> Organization:
> 
> Implementation Name:
> 
> Description:
> 
> Maturity:
> 
> Coverage:
> 
>   For each section, indicate if implemented or not.
> 
>   6.3: unique discriminator per session
> 
>   6.4: Echo Function
> 
>   6.5: Poll Sequence
> 
>   6.6: Demand Mode
> 
>   6.7.2: Simple Password Authentication
> 
>   6.7.3: Keyed MD5 and Meticulous Keyed MD5 Authentication
> 
>   6.7.4: Keyed SHA1 and Meticulous Keyed SHA1 Authentication
> 
>   6.8.1: State Variables (indicate individual conformance)
>     bfd.SessionState
>     bfd.RemoteSessionState
>     bfd.LocalDiscr
>     bfd.RemoteDiscr
>     bfd.LocalDiag
>     bfd.DesiredMinTxInterval
>     bfd.RequiredMinRxInterval
>     bfd.RemoteMinRxInterval
>     bfd.DemandMode
>     bfd.RemoteDemandMode
>     bfd.DetectMult
>     bfd.AuthType
>     bfd.RcvAuthSeq
>     bfd.XmitAuthSeq
>     bfd.AuthSeqKnown
> 
>   6.8.2: Timer Negotiation
> 
>   6.8.3: Timer Manipulation
> 
>   6.8.4: Detection Time Calculation
> 
>   6.8.5: Echo Function Failure Detection
> 
>   6.8.6: Reception of BFD Control Packets
> 
>   6.8.7: Transmitting BFD Control Packets
> 
>   6.8.8: Reception of BFD Echo Packets
> 
>   6.8.9: Transmission of BFD Echo Packets
> 
>   6.8.10: Min Rx Interval Change
> 
>   6.8.11: Min Tx Interval Change
> 
>   6.8.12: Detect Multiplier Change
> 
>   6.8.13: Enabling or Disabling The Echo Function
> 
>   6.8.14: Enabling or Disabling Demand Mode
> 
>   6.8.15: Forwarding Plane Reset
> 
>   6.8.16: Administrative Control
> 
>   6.8.17: Concatenated Paths
> 
>   6.8.18: Session Hold Down
> 
>   9: Generalized TTL Security Mechanism
> 
> Licensing:
> 
> Implementation Experience:
> 
> Comments (optional):
> 
> Contact Information:
> 
> Date:


Mahesh Jethanandani
[e-mail]