Re: [Lsvr] AD Review of draft-ietf-lsvr-bgp-spf-19

[Acee Lindem <[e-mail]>]

You are right, my review Email was truncated. 
Thanks,
Acee

> On Mar 9, 2023, at 3:45 PM, Alvaro Retana <[e-mail]> wrote:
> 
> On March 9, 2023 at 2:41:17 PM, Acee Lindem wrote:
> 
> Acee:
> 
> Hi!
> 
> It looks like the review was truncated, you replied up to line 372,
> but the complete review goes all the way to line 1513. :-(
> 
>   https://mailarchive.ietf.org/arch/msg/lsvr/80Awa3weqFJC5G--ep0EZVYFfmc/
> 
> 
> ...
>>> My main concern is still the lack of semantic checking (see my
>>> comments in §7.*). BGP-LS (rfc7752bis) only does syntactic validation
>>> because any semantic checking is left to the BGP-LS Consumer (and the
>>> specifics left out of scope). The way BGP SPF uses the information is
>>> different (all the nodes run SPF), so the validity of the contents
>>> need to be verified
>> 
>> Keyur and I discussed and we’re not sure you think is missing.
> 
> This is an example (comment at line 1513):
> 
> =====
>   [major] The validation in rfc7752bis is syntactic, checking that the lengths
>   are ok, etc.  What about semantic validation?  For example, if TLV 516 is
>   present, but the value of the ID is 0, what should the receiver do?  Is the
>   TLV valid?  Is the Node Descriptor valid?  Is the NLRI valid?
> 
>   This is just an example -- we should go through all the TLVs.  Note that none
>   of the BGP-LS documents talk about semantic validation, so there isn't a
>   place to point to :-( because the Consumer is expected to take care of that -
>   - and how it operates is out of scope.  IOW, BGP-LS can be a garbage-in-
>   garbage-out transport from a semantic point of view, but BGP SPF can't!
> =====
> 
> 
> 
> Alvaro.