Cogent & HE

Jimmy Hess mysidia at
Fri Jun 10 00:18:49 UTC 2011

On Thu, Jun 9, 2011 at 6:49 PM, Richard A Steenbergen <ras at> wrote:
> On Thu, Jun 09, 2011 at 06:26:01PM -0500, Jimmy Hess wrote:

You seem to have missed it, so I will say again: IPv6 is not IPv4.
They are two different internetworks, with different participants -- many
IPv4 networks have no IPv6 counterpart as of yet.
Having any kind of IPv6 network is a new thing for Cogent;
they opened shop, when, 2008, sometime?

I'm pretty sure HE had an IPv6 network and a greater degree of connectivity,
before you could get IPv6 from Cogent.

Many Tier1 IPv4 networks had no IPv6 network for a long time;
the first day an IPv4 Tier1 turns on IPv6 doesn't magically make
them IPv6 Tier1 --  because the v6 network has a different topology,
there are many 'holes' in the graph,  where the new network's peering
arrangements will be IPv4 only.

An IPv4 Tier1 might actually need to buy transit to get connected
to the IPv6 internet, if they are sufficiently late for the show.

There is a chance IPv4 and IPv6 topologies will become more similar
in the future, but for now that is not the case, and  that is no reason to
confuse the two networks, or speak as if they are one and the same.

Cogent doesn't have a transit-free global IPv6 network view.

> Cogent is (unfortunately, note I have no particular love for Cogent
> here) a transit free network, who peers with every other Tier 1. HE is a

No,  Cogent has a transit free IPv4 network;  Cogent peers with every
other IPv4 Tier 1.
It appears as if they are trying to use their IPv4 Tier1 status as a
strategic piece, to attempt
to get Tier1 status on the IPv6 network.

That might work well with other Tier1s who are also behind in IPv6 deployment,
and possibly apt to peer with Cogent.

But that effort doesn't automatically make Cogent a Tier1 on the  IPv6 network.
We'll just have to wait and see about that, I think.

> perfectly fine network, but they are not even CLOSE to a transit free
> network. HE buys transit from multiple other networks, including

You mean HE is not close to being a transit free IPv4 network.
They have a very nearly transit-free IPv6 network.

> There is absolutely NO requirement that there be a direct
> interconnection between HE and Cogent. None, period, and if you think
> otherwise you are vastly confused about routing on the Internet. Let me
> say this again, there is NO requirement that HE buy transit from Cogent,
> but there is a requirement that HE buy transit from *SOMEONE* if they
> are not a transit free network.

HE doesn't need to buy IPv6 transit, because they are in effect transit-free
(except to Cogent).

> HE has deliberately chosen NOT to use transit for their IPv6 routes, in
> order to force people like Cogent to peer with them so they can become
> an "IPv6 Tier 1", and thus you have a partition. These are the same


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