Re: [Pce] Alvaro Retana's No Objection on draft-ietf-pce-lsp-control-request-09: (with COMMENT)

[Dhruv Dhody <[e-mail]>]

Hi Alvaro,

Let me take a stab at this. Authors can join in -

On Fri, Sep 27, 2019 at 3:38 PM Alvaro Retana via Datatracker
<[e-mail]> wrote:
>
> Alvaro Retana has entered the following ballot position for
> draft-ietf-pce-lsp-control-request-09: No Objection
>
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> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
>
> I have a substantive comment and then some nits/editorial notes.
>
> (1) It seems to me that any PCE can request control of an LSP.  Even if the
> sessions are authenticated and encrypted, how does the PCC determine if it's ok
> for the requesting PCE to ask for control?  §8.1 says that an "implementation
> SHOULD allow the operator to configure the policy based on which it honors the
> request to control the LSPs".  If the implementation doesn't allow the
> configuration of policy, then it is possible for a rogue PCE to ask for control
> of an LSP, and for the PCC to grant it.  Why is the ability to configure this
> policy not REQUIRED?  I believe this case should be explicitly called out as a
> vulnerability.
>

Thanks for pointing this out. Since RFC 8231 uses SHOULD wrt policy, I
would consider not changing that. We can highlight that the PCC is the
ultimate arbiter on if the delegation should be made and to which PCE.
Even after delegation, the PCC can take back control anytime. But at
the same time blindly accepting control request could be a problem!

I propose this text in Security section -

   A PCC is the ultimate arbiter of delegation.  As per [RFC8231], a
   local policy at PCC is used to influence the delegation.  A PCC can
   also revoke the delegation at any time.  A PCC MUST NOT blindly trust
   the control requests and SHOULD take local policy and other factors
   into consideration before honoring the request.

> (2) Abstract: s/A Path Computation Client (PCC) has set up LSPs/A Path
> Computation Client (PCC) that has set up LSPs
>
> (3) §1: s/which PCE to delegate the orphaned LSP/which PCE to delegate the
> orphaned LSP to
>
> (4) §1: s/a simple extension, by using this a PCE can/a simple extension, by
> using it a PCE can
>
> (5) In §3 the new C Flag is called the "LSP-Control Request Flag", but §7.1
> only uses "LSP-Control".  Please be consistent; the more descriptive name is
> probably better.
>
>

These all looks like reasonable requests, authors - please update!

Thanks!
Dhruv