Re: [Lsr] https://tools.ietf.org/html/draft-wang-lsr-prefix-unreachable-annoucement-05

Aijun Wang <wangaijun@tsinghua.org.cn> Tue, 09 March 2021 00:19 UTC

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From: Aijun Wang <wangaijun@tsinghua.org.cn>
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Date: Tue, 9 Mar 2021 08:19:08 +0800
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Cc: Gyan Mishra <hayabusagsm@gmail.com>, "Acee Lindem (acee)" <acee@cisco.com>, Aijun Wang <wangaj3@chinatelecom.cn>, draft-wang-lsr-prefix-unreachable-annoucement <draft-wang-lsr-prefix-unreachable-annoucement@ietf.org>, lsr <lsr@ietf.org>
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To: Tony Li <tony.li@tony.li>
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Subject: Re: [Lsr] https://tools.ietf.org/html/draft-wang-lsr-prefix-unreachable-annoucement-05
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Hi, Tony:

There are two scenarios as introduced by Gyan: one is the node failure(Scenario 1), and another is the link failure(Scenario 2).

For scenario 1, also when all ABRs can’t reach the specified address, it is not efficient to advertise all of other detail prefixes when only one prefix or some prefixes are missing. The ABRs  tell exactly the specified failure prefixes via PUA message is reasonable.

For scenarios 2, because the specified prefixes can be accessed via another ABR, then we can let this ABR to advertise the details prefixes information for the specified address, which behavior is similar with RIFT, as also mentioned in the presentation materials.

Aijun Wang
China Telecom

> On Mar 9, 2021, at 08:03, Tony Li <tony.li@tony.li> wrote:
> 
> 
> 
> Gyan,
> 
> If I understand the purpose of this draft, the point is to punch a hole in a summary so that traffic is redirected via an alternate, working path.
> 
> Rather than punch a hole, why not rely on existing technology? Have the valid path advertise the more specific. This will attract the traffic.
> 
> Tony
> 
> 
>> On Mar 8, 2021, at 3:57 PM, Gyan Mishra <hayabusagsm@gmail.com> wrote:
>> 
>> 
>> Acee. 
>> 
>> Please ask the two questions you raised about the PUA draft so we can address your concerns.
>> 
>> If anyone else has any other outstanding questions or concerns we would like to address as well and resolve.
>> 
>> Once all questions and  concerns are satisfied we would like to ask for WG adoption.
>> 
>> Kind Regards 
>> 
>> Gyan
>> -- 
>> 
>> 
>> Gyan Mishra
>> Network Solutions Architect 
>> M 301 502-1347
>> 13101 Columbia Pike 
>> Silver Spring, MD
>> 
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>