Re: [sidr] [Idr] AS_SET depreciation (RFC6472) and BGP multipath

Jakob Heitz <> Tue, 27 March 2012 23:22 UTC

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From: Jakob Heitz <>
To: "" <>, Tony Li <>
Date: Tue, 27 Mar 2012 19:22:09 -0400
Thread-Topic: [Idr] AS_SET depreciation (RFC6472) and BGP multipath
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Subject: Re: [sidr] [Idr] AS_SET depreciation (RFC6472) and BGP multipath
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SIDR wise, to aggregate routes, you would have to
aggregate signatures. That means to put both signatures
into the aggregate and sign across the pair of them
at each subsequent hop. yuck.

Alternatively, send both routes and let the end
user decide to use them in a multipath.
Can you say ebgp add-path?

Jakob Heitz.

-----Original Message-----
From: [] On Behalf Of Robert Raszuk
Sent: Tuesday, March 27, 2012 1:57 PM
To: Tony Li
Cc: List
Subject: Re: [Idr] AS_SET depreciation (RFC6472) and BGP multipath

Hi Tony,

>> * Propose an alternative encoding to address this case specifically
>> for multipath use cases, but till this is deployed continue use
> Another option might be to simply concatenate AS_PATHs.  Yes, this
> would lose policy information and mis-represent AS topology to
> management stations and the like, but it would not create any risk of
> looping and would not require us to reinstitute AS_SET.

Very true. However I am not sure how that would be effectively that much 
different SIDR wise from issue with AS_SET ;)

Said this are there any other issues with AS_SET then SIDR ?


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