Cogent and Google no longer peered via IPv6

Frank Bulk frnkblk at
Wed May 4 15:11:08 CEST 2011

Yes, we're receiving 15169 from Cogent.


-----Original Message-----
From: Martin Millnert [mailto:martin at] 
Sent: Monday, May 02, 2011 11:28 PM
To: frnkblk at
Cc: 'Phil Benchoff'; ipv6-ops at
Subject: RE: Cogent and Google no longer peered via IPv6


On Mon, 2011-05-02 at 22:44 -0500, Frank Bulk wrote:
> We get to via Sprint today, even though we are IPv6-peered
> with Cogent and Qwest and have (had?) an HE tunnel as well.  

A simple check for _15169_ among your received v6-prefixes from Cogent
would be useful then. :)

> I used RIPE's bgplay and there was no indication of routing changes
> for Google's IPv6 prefix.

That doesn't contradict Phil's observation:
  I just checked 2001:4800::/23 in RIS, and I see zero paths via 174 to
it, despite at least one RIS full peer having 174-transit according to
IRR data.


> Frank
> -----Original Message-----
> From: at
> [ at] On Behalf Of
> Phil Benchoff
> Sent: Monday, May 02, 2011 7:27 PM
> To: ipv6-ops at
> Subject: Cogent and Google no longer peered via IPv6
> As of Thursday 28 April at about noon (EDT) most of our  IPv6 inbound
> traffic
> shifted to our backup ISP.  A little digging shows that we are receiving no
> routes from AS15169 (Google) via Cogent.  They are no longer peered via
> IPv6.
> No HE and no Google.  That somewhat limits the usefulness of our IPv6
> connectivity via Cogent.
> Anybody else notice this?
> Phil

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