Hi, Ketan:

 

Thanks for your comments.  But I should correct some of them:

1)     In the updated version, the indication of prefix unreachability is still 
the “NULL” value of prefix originator, not the LSInfinity.

2)     The LSInfinity is used only for avoiding the misrouting by 
implementation not support this implementation, as you have also pointed out.  
As pointed out also in the draft, when all the nodes within the area support 
such capabilities, the LSInfinity value can be ignored:

 

“If not all of nodes within one area support the PUAM capabilities,
   the PUAM message should be advertised with the associated prefix cost
   set to LSInfinity.  According to the description in [RFC2328 
<https://datatracker.ietf.org/doc/html/rfc2328> ],
   [RFC5305 <https://datatracker.ietf.org/doc/html/rfc5305> ] and [RFC5308 
<https://datatracker.ietf.org/doc/html/rfc5308> ], the prefix advertised with 
such metric value
   will not be considered during the normal SPF computation, then such
   additional information will avoid the misbehavior of the nodes when
   they don't recognize the PUAM message.
 
   If all of nodes within one area support the PUAM capabilites, the
   PUAM message can be safely advertised without the additional
   LSInfinity metric information.”

 

 

We are glad to cooperate with Peter to forward the solution, but want to say 
LSInfinity only can’t be used to indicate the unreachable information, we need 
some explicit indication method.

 

 

Best Regards

 

Aijun Wang

China Telecom

 

发件人: [email protected] [mailto:[email protected]] 代表 Ketan Talaulikar
发送时间: 2022年7月27日 16:36
收件人: [email protected]
抄送: lsr <[email protected]>
主题: [Lsr] Comments on draft-wang-lsr-prefix-unreachable-annoucement

 

Hello Authors,

 

I am sharing some comments on the latest version of this document since we seem 
to have a packed agenda in LSR this time.

 

1) I notice that in the latest update of the draft, there is a big change to 
start using LSInfinity for indicating prefix unreachability (similar to 
draft-ppsenak-lsr-igp-ureach-prefix-announce). I see this as a sign of a degree 
of convergence between the two drafts.

 

2) However, I then question the motivation of the authors to continue with the 
bad design of overloading Prefix Originator and the added capability stuff on 
top. I don't wish to repeat why that design was an absolute NO-GO for me and I 
am glad to see the authors acknowledge the problem with misrouting by 
implementations not supporting this specification. So I don't see the point of 
still retaining all that. 

 

Thanks,

Ketan

 

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