Dear authors:

In parallel with the WG adoption call, here's my review of this document.
Please consider the comments with other input you may receive.

As I mentioned in the adoption thread, I would like to see Operational
Considerations about the interaction of the criteria defined here and the
use of Eligibility (draft-ietf-spring-sr-policy-eligibility). These
considerations could belong in this draft, or you can collaborate to
develop a common understanding.

Thanks!

Alvaro.

[Line numbers from idnits.]


...
77 1.  Introduction

79   SR Policy architecture are specified in [RFC9256].  An SR Policy

[nit] s/architecture are/architecture is



...
89   This document defines the new candidate path validity criterions
90   based on [RFC9256].  For the segment list invalidation rules, refer
91   to [RFC9256] and [I-D.liu-spring-sr-policy-flexible-path-selection].
92   This document does not change the segment list invalidation rules.

[major] The New validity criteria are based on rfc9256.  It is too early to
determine the impact (on rfc9256) that
I-D.liu-spring-sr-policy-flexible-path-selection will have. Remove the
reference.



...
135 3.  Validity of a Candidate Path

137   A headend MAY be informed about the validity control parameters of a
138   candidate path for an SR Policy <Color, Endpoint> by various means
139   including: via configuration, PCEP, or BGP.  The detailed protocol
140   extension will be described in a separate document.

[major] s/MAY/may

In this case, "MAY" states a fact and is not needed for interoperability.



...
175   candidate path is considered valid only if both validity control
176   parameters are satisfied.

[nit] s/candidate path/A candidate path



178   If both the Minimum Valid SL Count and the Minimum Cumulative SL
179   Weight are set to 0, The validity of candidate paths must be
180   determined according to the mechanism defined in [RFC9256].

[minor] s/set to 0, The validity of candidate paths must be/set to 0, the
validity of candidate paths is



...
210 6.  Security Considerations

212   The security considerations of segment routing in [RFC9256] are
213   applicable to this document.

[major] Changing the validity criteria is not without potential issues.
For example, a rogue operator may misconfigure the new validity parameters,
making the conditions impossible to meet (or too easy), resulting in a
deterioration or even an inability to provide the service . IMO, this is
new (with respect to rfc9256) and should be mentioned.

For example... Focusing on the Minimum Valid SL and considering the example
in Figure 1, it's easy to see that the correct configuration is 2 (as
explained in Section 4). However, it would be easy for an attacker (a rogue
employee, for example) to configure this parameter as 1 or 3...  A value of
1 would result in the problem this draft is trying to solve: a
deterioration of the service, while a value of 3 would result in the CP
never being valid (because there are only 2 SLs). One could consider both
cases to be DoS attacks.

[EoR-07]
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