How big is the Internet?

Leo Bicknell bicknell at
Thu Aug 15 14:05:26 UTC 2013

On Aug 14, 2013, at 3:27 PM, Patrick W. Gilmore <patrick at> wrote:

> Once you define what you mean by "how bit is the Internet", I'll be happy to spout off about how big it is. :)

Arbitrary definition time: A Internet host is one that can send and receive packets directly with at least one far end device addressed out of RIR managed IPv4 or IPv6 space.

That means behind a NAT counts, behind a firewall counts, but a true private network (two PC's into an L2 switch with no other connections) does not, even if they use IP protocols.  Note that devices behind a pure L3 proxy do not count, but the L3 proxy itself counts.

Now, take those Internet hosts and create a graph where each node has a binary state, forwards packets or does not forward packets the result is a set of edge nodes that do not forward packets.  The simple case is an end user PC, the complex case may be something like a server in a data center that while connected to multiple networks does not forward any packets, and is an edge node on all of the networks to which it is attached.

To me, "all Internet" traffic is the sum of all "in" traffic on all edge nodes.  Note if I did my definition carefully out = in - (packet loss + undeliverable), which means on the scale of the global Internet I suspect out == in, when rounded off.

So please, carry on and spout off as to how big that is, I think an estimate would be very interesting.

       Leo Bicknell - bicknell at - CCIE 3440
        PGP keys at

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