Is there list of IXPs (containing the information of the AS# of the IXP)

Jeroen Massar jeroen at
Mon Dec 22 14:52:07 UTC 2014

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

> 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?


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