Re: [Lsr] Fwd: New Version Notification for draft-ietf-ospf-ospfv2-hbit-09.txt

[Padma Pillay-Esnault <[e-mail]>]

I looked at the suggested change and I have no objections removing the term
"permanent".

Will make all changes in the next version.

Thanks
Padma

On Wed, Sep 25, 2019 at 12:06 PM Alvaro Retana <[e-mail]>
wrote:

> On September 23, 2019 at 3:29:55 PM, Padma Pillay-Esnault (
> [e-mail]) wrote:
>
> Padma:
>
> Hi!
>
> (1) §3 (last paragraph) introduces different behavior for permanently vs
>> temporarily acting as a host.  From the point of view of the H-bit, what is
>> the difference?  It seems to me that in both cases the H-bit would be set:
>> the router would be acting as a host NOW.  How long it keeps the H-bit set
>> seems to be the distinction between permanent and temporary...but the
>> behavior should not change because of that.  IOW, the specification of what
>> happens when the H-bit is set should be singular -- you may be able to
>> soften some of the MUSTs (to SHOULD) if the exceptions are justified other
>> than using time.
>>
>> PPE > I agree that the the specification should be singular.
>
>
> I propose this change
> OLD:
> Therefore, non-local IPv4 prefixes, e.g., those
>    exported from other routing protocols, MUST NOT be advertised in AS-
>    external-LSAs for routers acting permanently as a host.
>
> NEW:
> Therefore, non-local IPv4 prefixes, e.g., those
>    exported from other routing protocols, SHOULD NOT be advertised in AS-
>    external-LSAs for routers acting permanently as a host.
>
> The last sentence below the MUST is correct to correctly repel.
> Current : In addition to the procedure described above, temporary host
> routers advertising type
> 2-metric External LSAs MUST set the metrics to LSInfinity to repel
> traffic.(see Section 6 of this document).
>
> The proposed changes didn’t eliminate the duality between permanent and
> temporary.  We need to eliminate that!  Said another way: how would the
> router know the difference in behavior between a permanent setting and a
> temporary one?  What is the time limit between temporary/permanent?  …
>
> NEW (suggestion)>
>
>    When the H-bit is set the host router cannot act as an AS Boundary
> Router
>
>    (ASBR).  Indeed, ASBR are transit routers to prefixes that are
> typically
>
>    imported through redistribution of prefixes from other routing
> protocols.
>
>    Therefore, non-local IPv4 prefixes, e.g., those imported from other
> routing
>
>    protocols, SHOULD NOT be advertised in AS-external-LSAs if the H-bit is
>
>    set.  Some use cases, such as an overloaded router or a router being
>
>    gracefully isolated, may benefit from continued advertisement of
> non-local
>
>    prefixes. In these cases, the type 2-metric in AS-external-LSAs MUST be
> set
>
>    to LSInfinity to repel traffic.(see Section 6 of this document).
>
>
> I’ll start the IETF Last Call when -10 is submitted.
>
> Thanks!
>
> Alvaro.
>