Re: [secdir] secdir review of draft-ietf-ospf-node-admin-tag-05

["Acee Lindem (acee)" <[e-mail]>]

Hi Ben, 

On 10/13/15, 7:02 PM, "Acee Lindem (acee)" <[e-mail]> wrote:

>
>
>On 10/13/15, 6:57 PM, "Benjamin Kaduk" <[e-mail]> wrote:
>
>>On Tue, 13 Oct 2015, Acee Lindem (acee) wrote:
>>
>>>
>>> On 10/13/15, 6:27 PM, "Benjamin Kaduk" <[e-mail]> wrote:
>>>
>>> >On Sun, 11 Oct 2015, Shraddha Hegde wrote:
>>> >
>>> >> >(easily) be unset.  Would force-expiring an LSA be enough to reset
>>>the
>>> >> >tag, or something else?
>>> >>
>>> >> Yes - this is standard for any OSPF LSA. However, since the OSPF RI
>>>LSA
>>> >> may include other TLVs or even other tags, a tag could also be
>>>withdrawn
>>> >> by reoriginating the RI LSA without the TLV or with a TLV that
>>>doesn’t
>>> >> include the withdrawn tag.
>>> >
>>> >I may still be confused, but I did not interpret the text in that way.
>>> >That is, the text about "all instances of the RI LSA originated by
>>>that
>>> >node".  (Which I changed to "instances of RI LSAs" in my grammar
>>>edits,
>>> >possibly incorrectly if I'm still confused.)  I was interpreting the
>>>word
>>> >"instances" to include historical ones over time, so that even if an
>>>RI
>>> >LSA carrying a particular admin tag was replaced by a different RI LSA
>>> >for the same advertising router, the old one would still be an
>>>instance of
>>> >that RI LSA.  Going back to RFC 2328, I'm not sure what exactly I had
>>>in
>>> >mind in terms of ages and scopes and sequence numbers that would cause
>>> >this
>>> >situation, but I somehow had it in my mind that there could be
>>>multiple RI
>>> >LSAs active at the same time that apply to a given node, such as if
>>>the
>>> >admin just added a new RI LSA containing only the admin tag to augment
>>>the
>>> >existing RI LSAs being sent.  Is that possible?
>>>
>>> In OSPF, a more-recent version or instance of an LSA will always
>>>supersede
>>> all previous instances of the same LSA.
>>
>>Thanks for clarifying.  So, this is a non-issue, and the only question is
>>whether the text could/should be changed to improve clarity.
>
>Let me think about this since it is a generic OSPF RI ambiguity and it
>will affect multiple documents. In a WebEx right now though…

The key point here is that an OSPF router only maintains the most-recent
instance of an LSA in its Link-State Database. So, there shouldn’t be any
ambiguity. Perhaps, the text could be changed to “all RI LSA instances in
the Link-State Database (LSDB) advertised by the corresponding OSPF
router.” 

Thanks,
Acee 

     

          


>
>Thanks,
>Acee
>
>
>
>>
>>-Ben
>