Re: [secdir] secdir review of draft-ietf-isis-sbfd-discriminator-02

"Les Ginsberg (ginsberg)" <> Wed, 18 November 2015 04:31 UTC

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From: "Les Ginsberg (ginsberg)" <>
To: Tom Yu <>, "" <>, "" <>, "" <>
Thread-Topic: secdir review of draft-ietf-isis-sbfd-discriminator-02
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Date: Wed, 18 Nov 2015 04:31:53 +0000
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Subject: Re: [secdir] secdir review of draft-ietf-isis-sbfd-discriminator-02
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Tom -

Thanx for the review.

If you are not happy with the Security section of the base S-BFD draft it seems to me it makes the most sense to address any issues in that document. Trying to make up for any shortcomings in S-BFD draft by adding to  the IGP drafts (there is a similar OSPF S-BFD draft) when the IGPs are merely acting as a transport for opaque information (as you say) does not seem appropriate to me.

Can we close on this issue?


> -----Original Message-----
> From: Tom Yu []
> Sent: Tuesday, November 17, 2015 7:06 PM
> To:;; draft-ietf-isis-sbfd-
> Subject: secdir review of draft-ietf-isis-sbfd-discriminator-02
> I have reviewed this document as part of the security directorate's ongoing
> effort to review all IETF documents being processed by the IESG.  These
> comments were written primarily for the benefit of the security area
> directors.  Document editors and WG chairs should treat these comments
> just like any other last call comments.
> Summary: ready with nits
> I agree with the first paragraph of the Security Considerations, in that I think
> it's unlikely that this document introduces security risks for IS-IS, which as I
> understand it, effectively transports the proposed S-BFD discriminators as an
> uninterpreted opaque payload.
> The second paragraph
>    Advertisement of the S-BFD discriminators does make it possible for
>    attackers to initiate S-BFD sessions using the advertised
>    information.  The vulnerabilities this poses and how to mitigate them
>    are discussed in the Security Considerations section of [S-BFD].
> refers to the Security Considerations of the [S-BFD] base document.  The [S-
> BFD] Security Considerations describe some strengthening practices, but
> doesn't seem to describe the vulnerabilities in significant detail.
> [S-BFD] Security Considerations seems to describe an attack where someone
> impersonates the responder, but not one where someone impersonates an
> initiator.
> Other sections of [S-BFD] might imply the existence of this sort of
> vulnerability, but the Security considerations seems not to mention it
> explicitly.  I'm not sure whether it's best to leave things alone, revise this
> document, or revise [S-BFD].
> -Tom