Re: [Idr] Fwd: I-D Action:draft-keyur-bgp-enhanced-route-refresh-00.txt

Hi, Qing:

Please see my comments inline.

On 10/9/10 1:03 AM, Qing Zeng wrote:
> Hi All:
>
> I have some questions:
> 1. This is the method to checking for possible missing withdraws between BGP speakers,
> what's the most likely to occur application scenario of  possible missing withdraws?

It provides a way to detect inconsistencies and to force consistency 
over a established session.  Dealing with missing withdraws (caused by 
software bugs) is one of the applications.  Yes, there have been a few 
occurrences in the past.

>
>
> 2. Why don't consider that using End-of-RIB(EOR) or extension-UPDATE message to
> mark the beginning and the ending of a route refresh? After all, the EOR is more often
> used to mark completion of the whole Rib update for routing convergence.
>    

The End-of-Rib as currently defined and used for GR is not adequate for 
the current purpose as:

      - there is no beginning.
      - in the case of continuous churn, we do not want the End-of-Rib 
to be delayed like the end-of-refresh.

Also, extending the route refresh seems more logical than extending the 
UPDATE message in this case.

> 3. How to operate when BGP speaker is sending Adj-Rib-Out due to refresh with route oscillation?
> For correctly identifing the beginning and the ending of a route refresh , should route selection be hold on the speaker?
>    

In case of continuous churn,  an implementation should support a locally 
configurable upper bound for generating the end-of-refresh.  One way is 
to suspend the inbound processing briefly.  That should be optional 
(will revise in the next version).   Another way is to just generate the 
end-of-refresh.   There is little practical difference between the 
approaches for a route that keeps churning.

Thanks.   -- Enke

> Best Regards!
> Qing
>
>
>
>
> ----- 原始邮件 -----
> 发件人: "Enke Chen"<enkechen@cisco.com>
> 收件人:<idr@ietf.org>
> 抄送: "Keyur Patel"<keyupate@cisco.com>
> 发送时间: 2010年10月7日 2:42
> 主题: [Idr] Fwd: I-D Action:draft-keyur-bgp-enhanced-route-refresh-00.txt
>
>
>    
>> FYI.  Will appreciate comments.
>>
>> -- Enke
>>
>> -------- Original Message --------
>> Subject: I-D Action:draft-keyur-bgp-enhanced-route-refresh-00.txt
>> Date: Tue, 5 Oct 2010 22:00:02 -0700 (PDT)
>> From: Internet-Drafts@ietf.org
>> Reply-To: internet-drafts@ietf.org
>> To: i-d-announce@ietf.org
>>
>>
>>
>> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>>
>> Title           : Enhanced Route Refresh Capability for BGP-4
>> Author(s)       : K. Patel, et al.
>> Filename        : draft-keyur-bgp-enhanced-route-refresh-00.txt
>> Pages           : 6
>> Date            : 2010-10-05
>>
>> In this document we enhance the existing BGP route refresh mechanisms
>> to provide for the demarcation of the beginning and the ending of a
>> route refresh.  The enhancement can be used to facilitate on-line,
>> non-disruptive consistency validations of BGP routing updates.
>>
>> A URL for this Internet-Draft is:
>> http://www.ietf.org/internet-drafts/draft-keyur-bgp-enhanced-route-refresh-00.txt
>>
>> Internet-Drafts are also available by anonymous FTP at:
>> ftp://ftp.ietf.org/internet-drafts/
>>
>> Below is the data which will enable a MIME compliant mail reader
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>> Internet-Draft.
>>
>>
>>
>>      
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