[176974] in North American Network Operators' Group
Re: Is there list of IXPs (containing the information of the AS#
daemon@ATHENA.MIT.EDU (Jeroen Massar)
Mon Dec 22 09:55:34 2014
X-Original-To: nanog@nanog.org
Date: Mon, 22 Dec 2014 15:52:07 +0100
From: Jeroen Massar <jeroen@massar.ch>
To: refresh.lsong@gmail.com, Nick Hilliard <nick@foobar.org>,
nanog@nanog.org, Randy Bush <randy@psg.com>
In-Reply-To: <54982E72.8040804@gmail.com>
Errors-To: nanog-bounces@nanog.org
On 2014-12-22 15:45, Song Li wrote:
> 在 2014/12/22 22:26, Nick Hilliard 写道:
>> On 22/12/2014 13:50, Jeroen Massar wrote:
>>> IXs themselves do not have ASNs, as they are Layer 2 providers.
>>
>> most modern IXPs will have an ASN for their route server, and possibly a
>> separate asn for their mgmt infrastructure.
>>
>> Not sure how useful the mgmt ASN is, although most IXPs will
>> paradoxically
>> include this on their list of members.
>>
>> Nick
>>
>>
> Thanks for your help!
>
> I studied all the AS-Path in the routing table (from routeviews and
> RIPE), and found that some ASN of IXPs were included in some AS-Path.
You are likely seeing IP addresses from the peering LAN, which typically
have addresses that are under the ASN from an IX.
Quite a few IXes state that the peering prefixes should not be announced
world-wide.
> I think that under normal circumstances they should not appear in the
> AS-Path, hence i want to filter out them.
"Filtering them out" will have fun results when a valid ICMP is being
returned. Something about "Packet Too Big"...
What is the reason for thinking you need to filter these?
Greets,
Jeroen
