On 2011-04-10 03:13, Geoff Huston wrote:
> On 09/04/2011, at 10:34 PM, Brian E Carpenter wrote:
> 
>> Please see attached review.
>>
>> <draft-ietf-sidr-roa-validation-10-carpenter.txt>
> 
> 
> 
> Thanks Brian,
> 
> I'm not sure as to the appropriate form of response, but let me respond to 
> the two minor issues you identified in this review (many thanks for the 
> review, by the way)

This is just fine... the gen-art archive is public, so replying here
is on the record.

>> 3.  Applying Validation Outcomes to Route Selection
> ...
>>      "valid" is to be preferred over
>>      "unknown", which is to be preferred over
>>      "invalid".
> ...
>>   It is a matter of local routing policy as to the actions to be
>>   undertaken by a routing entity in processing those routes with
>>   "unknown" validity states.
> 
> you commented that: 
> 
> That seems to leave open the possibility that an aggregated route (which
> is by definition "unknown") would be rejected. Assuming that the various
> separate routes that were aggregated together never reached this particular
> router, the result would be a black hole. At the least, it seems that this
> should be mentioned, even if it is an intentional possibility.
> 
> But the next sentence in the document states:
> 
>    Due to considerations of partial use of
>    ROAs in heterogeneous environments, such as in the public Internet,
>    it is advised that local policy settings should not result in
>    "unknown" validity state outcomes being considered as sufficient
>    grounds to reject a route outright from further consideration as a
>    local "best" route.

Yes, indeed, and all I was thinking of was adding a sentence here saying
that the "unknown" category might include aggregates. It's a direct implication
of the earlier text but I tend to assume that not all readers will
notice all implications.

> Also, given the current proposal in the IDR WG to deprecate the use
> of AS Sets (and by implication deprecate the (rarely used if ever)
> practice of proxy aggregation, I am unsure of the need to call out 
> proxy aggregation in this context.

I won't get into that debate ;-)

>> 5.  Route Validation Lifetime
>>
>>   The "lifetime" of a validation outcome refers to the time period
>>   during which the original validation outcome can be still applied.
>>   The implicit assumption here is that when the validation lifetime
>>   expires the routing object should be re-tested for validity.
> 
> you commented that:
> 
> OK, but shouldn't a previously "valid" route be downgraded to
> "unknown" after the lifetime expires and until the validity has
> been re-tested?
> 
> Not necessarily. When a route is validated, the validation lifetime refers
> to the validation time of the EE cert used to sign that ROA. When the
> ROA is no longer valid the route should be re-tested for validity. It it
> possible that there is another ROA that still validates the route, or in the
> absence of the ROA that previously validated the route, the route may 
> be considered invalid (i.e. there is an AS 0 ROA still extant that encompasses
> this prefix). For this reason the text specifically indicates that the
> appropriate action is to retest the route for validity in the context of the
> current local cache of valid ROAs.

Yes, but I have no sense of the timing - would the time taken to revalidate
the route leave a long enough gap for some kind of security exposure while
an expired route was still marked as valid? Maybe I am worrying about
nothing.

> 
> 
> At this stage I am unsure if changes to the draft are warranted, as
> I believe that the issues you highlight here are addressed in the
> document as it stands.

Sure, these were minor comments, unless your shepherd feels differently.

   Brian
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