question about AS relationship

Christopher Morrow morrowc.lists at
Fri Feb 21 05:59:01 UTC 2014

On Fri, Feb 21, 2014 at 12:37 AM, Song Li <refresh.lsong at> wrote:
> Thanks. In order to prevent route leaking, this imformation should be
> provided to providers.
> but another question, should the AS relationships between customer and its
> other neighbors (downstrem/peer/another provider)  be private?

perhaps you should draw a little ascii art, I think you're asking:

DS1 - customer - you - isp

"can DS1's relationship to 'customer' be secret"

no. well, not if they want:
  1) to use a public ASN
  2) use ip space which isn't part of 'customer' aggregate
  3) want to be reachable on the internet

It's safe to say that your goal as an ISP and a customer of an ISP, should be:
  "Make sure that all of my routes and the routes of my customers and
their customers, that I'm expected to provide transit for, are in my
ISP's filters."

(and as someelse pointed out: "If they use BGP and expect global
reachabilty... then the information isn't private anyway.")

> --
> Sky Li
>> On Thursday, February 20, 2014 08:09:35 PM Christopher
>> Morrow wrote:
>>> so, yes. pleass tell your upstream your customers so
>>> proper filtering can be automated and implemented.
>>> don't turn up bgp customers without filtering, that kills
>>> kittens.
>> For all the leaking I've seen in the last four weeks
>> (including a well-known operator that was involved in the
>> Youtube/Pakistan saga + other well-known global operators
>> that could be classified as "a reasonably large tier"),
>> we're still a long way away ensuring all customer prefixes
>> are filtered correctly at the inter-domain peering edge. A
>> loooooooong way away...
>> Mark.

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