Re: [OSPF] Alvaro Retana's Discuss on draft-ietf-ospf-node-admin-tag-07: (with DISCUSS and COMMENT)

Shraddha Hegde <> Tue, 20 October 2015 04:04 UTC

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From: Shraddha Hegde <>
To: Shraddha Hegde <>, "Alvaro Retana (aretana)" <>, The IESG <>
Thread-Topic: Alvaro Retana's Discuss on draft-ietf-ospf-node-admin-tag-07: (with DISCUSS and COMMENT)
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Subject: Re: [OSPF] Alvaro Retana's Discuss on draft-ietf-ospf-node-admin-tag-07: (with DISCUSS and COMMENT)
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Resending the mail as the previous mail content got removed.


  Thanks for the discussion.
I am sorry that we are not able to reach conclusion quickly.

Nevertheless,I'll try to clarify based on my understanding of your comments.

If the same tag value is flooded with multiple scopes, then it will be declared conflicting (for all scopes).
  If there are policies that are dependent on those tags then they won't be applied

 <Shraddha> The conflicting tag won't be considered. Lets say a node had advertised 10 tags. Lets say 10th tag is conflicting and is arriving
                       In different scopes. Only 9 tags will be sent to policy. 
                       If you saying just because one tag is conflicting the whole set of tags for that node is ignored, then that's not the case.

 -- including policies that rely on more than one tag being present (including the one declared conflicting, of course).  The point of that question was to point out that by invalidating a tag the policies that will be applied won't always depend just on the remaining tags..

<Shraddha> Again I don't understand your statement. Why can't the policy be applied on only 9 tags in above example. If the policy fails because of the absence of 10th flag then it's an issue with the advertising router being nod-ABR and having advertised different tags in different scopes.

Do you mean to say we should not restrict same tag being advertised in different scopes?
I am not sure If we can change that at this stage of the document since WG as well as others who reviewed the document so far are OK with that restriction being there.


Again, the point was that by not allowing the tags to be tied to changes in topology you are not necessarily doing much to limit instability.
True, the topology may become unstable and the tags advertised will mirror that -- the root cause being the topology instability.  But I think there can be valid applications that could follow topology changes that won't mirror instability (if the network itself is stable).  Also, you focused on one thing (topology instability), leaving other reasons for tag instability without mention -- this last part was why I suggested that you might want to focus on the problem you really want to resolve and maybe talk about rate limiting.

<Shraddha> Personally, I do not think we need to talk about rate limiting of node-admin tags since we already have rate limiting for the LSA origination.
Would like to hear others opinion on this.


-----Original Message-----
From: Shraddha Hegde [] 
Sent: Tuesday, October 20, 2015 9:27 AM
To: Alvaro Retana (aretana) <>om>; The IESG <>
Cc: Acee Lindem (acee) <>om>;;;;;
Subject: RE: Alvaro Retana's Discuss on draft-ietf-ospf-node-admin-tag-07: (with DISCUSS and COMMENT)


I'll try to clarify based on my understanding of your comments.

If the same tag value is flooded with multiple scopes, then it will be declared conflicting (for all scopes).