i think the cogent depeering thing is a myth of some kind

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1

at <http://www.e-gerbil.net/cogent-t1r> there is a plain text document with
the following HTTP headers:

  Server: Apache/2.2.3 (Unix) PHP/5.2.3
  Last-Modified: Fri, 28 Sep 2007 19:15:53 GMT
  ETag: "92c1e1-a85-43b36ea5bcc40"
  Content-Length: 2693
  Content-Type: text/plain

the plain text title is:

  Cogent shows hypocrisy with de-peering policy

the plain text authorship is ascribed to:

  Dan Golding

the first plain text assertion that caught my eye was:

  Cogent, has, in fact, de-peered other Internet networks in the last 24
  hours, including content-delivery network Limelight Networks and
  wholesale transit provider nLayer Communications, along with several
  European networks.

since i appear to be reaching the aforementioned web server by a path that
includes cogent-to-nlayer, i think this part of the plain text is inaccurate.

traceroute to www.e-gerbil.net (69.31.1.2), 64 hops max, 52 byte packets
1 rc-main.f1.sql1.isc.org (204.152.187.254) 0.336 ms
2 149.20.48.65 (149.20.48.65) 0.509 ms
3 gig-0-1-0-606.r2.sfo2.isc.org (149.20.65.3) 1.163 ms
4 g0-8.core02.sfo01.atlas.cogentco.com (154.54.11.177) 2.757 ms
5 t4-2.mpd01.sfo01.atlas.cogentco.com (154.54.2.89) 2.958 ms
6 g3-0-0.core02.sfo01.atlas.cogentco.com (154.54.3.117) 2.525 ms
7 p6-0.core01.sjc04.atlas.cogentco.com (66.28.4.234) 4.183 ms
8 g3-3.ar1.pao1.us.nlayer.net (69.22.153.21) 2.637 ms
9 ge-2-1-1.cr1.sfo1.us.nlayer.net (69.22.143.161) 3.806 ms
10 so-0-2-0.cr1.ord1.us.nlayer.net (69.22.142.77) 69.022 ms
11 60.po1.ar1.ord1.us.nlayer.net (69.31.111.130) 69.491 ms
12 0.tge4-4.ar1.iad1.us.nlayer.net (69.22.142.113) 81.580 ms
...

the second plain text assertion which caught my eye was:

  Why is this happening? There are a few possibilities. First, Cogent
  may simply want revenue from the networks it has de-peered, in the
  form of Internet transit. Of course, few de-peered networks are
  willing to fork over cash to those that have rejected them. Another
  possibility is that Cogent is seeing threats from other peers
  regarding its heavy outbound ratios, and it seeks to disconnect
  Limelight and other content-heavy peers to help balance those ratios
  out.

this makes no sense, since dan golding would know that cogent's other peers
would not be seeing traffic via cogent from the allegedly de-peered peers.

so, i think the document is a hoax of some kind. (i saw it mentioned here.)

2

at <http://www.e-gerbil.net/cogent-t1r> there is a plain text document
with
the following HTTP headers:

  Date: Fri, 28 Sep 2007 21:56:34 GMT
  Server: Apache/2.2.3 (Unix) PHP/5.2.3
  Last-Modified: Fri, 28 Sep 2007 19:15:53 GMT
  ETag: "92c1e1-a85-43b36ea5bcc40"
  Content-Length: 2693
  Content-Type: text/plain

the plain text title is:

  Cogent shows hypocrisy with de-peering policy

the plain text authorship is ascribed to:

  Dan Golding

Clearly you can see the article was published by T1R in their Daily T1R
report: http://www.t1r.com/

(listed under "The Daily T1R Headlines")

If you subscribe to the Daily T1R, you can find Dan's report issued today.

since i appear to be reaching the aforementioned web server by a path that
includes cogent-to-nlayer, i think this part of the plain text is
inaccurate.

I think Dan overstepped here. Richard has made comments of a de-peering
notice received by nLayer, not an actual de-peering occurrence.

AFAIK, the only two networks in recent weeks that have been de-peered are WV
Fiber and LimeLight. WV was de-peered a couple on September 17th and
LimeLight was de-peered yesterday.

Randy

3

[snip]

the second plain text assertion which caught my eye was:

  Why is this happening? There are a few possibilities. First, Cogent
  may simply want revenue from the networks it has de-peered, in the
  form of Internet transit. Of course, few de-peered networks are
  willing to fork over cash to those that have rejected them. Another
  possibility is that Cogent is seeing threats from other peers
  regarding its heavy outbound ratios, and it seeks to disconnect
  Limelight and other content-heavy peers to help balance those ratios
  out.

this makes no sense, since dan golding would know that cogent's other peers
would not be seeing traffic via cogent from the allegedly de-peered peers.

The question makes no sense, since paul vixie would know that traffic
pushed away has to go somewhere. Specifically traffic formerly taking
the path
  (content net)->cogent
would take
  (content net)->(othernets)->cogent.

Given sufficent traffic analysis, one could determine some sets of
(content net) entities which would *likely* deliver a known-to-cogent
quantitiy of traffic over the complaining (othernets). Depending
what the silly ratio gobbledegook was the basis for complaints, and
how much existing
  (content customer)->cogent->(othernets)
needs to be 'balanced', the complaining (othernets) might just be
inviting their own complaints to be turned back on themselves...

4

Clearly you can see the article was published by T1R in their Daily T1R
report: http://www.t1r.com/

(listed under "The Daily T1R Headlines")

If you subscribe to the Daily T1R, you can find Dan's report issued today.

"Sorry, T1R.com requires Flash 8 or above: Get Flash"

I think Dan overstepped here. Richard has made comments of a de-peering
notice received by nLayer, not an actual de-peering occurrence.

ok.

AFAIK, the only two networks in recent weeks that have been de-peered are WV
Fiber and LimeLight. WV was de-peered a couple on September 17th and
LimeLight was de-peered yesterday.

it's still really hard to believe that dan golding, of all people, could have
written text that makes it seem as though traffic from one set of cogent's
peers would be seen as input from cogent by another set of cogent's peers.
i'll take your word for it, since you've got "Flash 8 or above", and i havn't.

are any of the de-peering letters online someplace?

5

Paul,

This is the scenario. Peer B is send lots of outbound to Peer A.

Peer A depeers Peer (well former Peer) B. Why? Well, Peer A is having ratio problems with other Peers C-F. Keep reading...

After depeering, some of (now former) Peer B's outbound traffic to Peer A will now flow over links from Peer B to Peers C-F, before finally terminating at Peer A. Peer A sees their ratios with Peers C-F improve.

This is a proven maneuver and Cogent is not the first to do it. Of course, it gets more complex with multihoming and the assumptions of a meshy enough connectivity to ensure this will happen.

This is better explained with a whiteboard. That full explanation was missing from the writeup that is posted (and I'll allow it to stay up for now), because that report was aimed at folks who may not be fully conversant in peering - financial professionals. BTW, thanks for dropping me an email to ask me about it, before posted to NANOG.

As far as reachability from one provider to another - I've heard that one can make routing changes quickly and easily on this crazy Internet thing. Perhaps in the 24 hours since I wrote that, a few changes occurred?

  Dan

6

I don't know that NLayer was depeered yesteray for a fact, although someone I trust did report that to me. I do know for a fact that Limelight was. No offense to the good folk at nLayer, but most of the people who I work for care a good bit more about Limelight

Didn't know about VW Fiber. Sorry, Randy - didn't mean to leave you guys out :slight_smile:

- Dan

7

This is a proven maneuver and Cogent is not the first to do it.

i guess that without knowing who else these de-peered networks are customers
of, it's hard for an outsider to guess which ratios into cogent's network by
other peers will improve as a result of de-peering these networks. had you
been writing for a technical audience i'm sure you would have alluded to this,
i'm sure. now that i know the article was a leak rather than a publication,
it all becomes clear.

... That full explanation was missing from the writeup that is posted (and
I'll allow it to stay up for now), because that report was aimed at folks
who may not be fully conversant in peering - financial professionals. BTW,
thanks for dropping me an email to ask me about it, before posted to NANOG.

the text i saw was so uncharacteristically non-dan-golding, that i really did
think it was a hoax. you're right that i should have asked you about it; in
my defense i was leaving for the weekend and didn't have as much time as this
should've gotten.

As far as reachability from one provider to another - I've heard that one
can make routing changes quickly and easily on this crazy Internet thing.
Perhaps in the 24 hours since I wrote that, a few changes occurred?

i'm a cogent customer, and my path to nlayer at the moment i read your note
still went through cogent. what was i to think? anyway, problem solved.