backbones filtering unsanctioned sites

Sat Feb 11 23:05:50 UTC 2017

> Looks like mostly proxy/torrent sites on that IP address.

That may be so. Maybe it isn’t particularly objectionable for Cogent
to not to carry traffic to some particular destination that they don’t like.
As you point out they already only offer a partial view of the Internet. 

What is very problematic is that they announce that this destination
is reachable via them, and then drop traffic. This is a problem for the
same reason that hijacking by announcing more specifics is a problem.
The bgp tables become no longer a source of truth about reachability.
If this kind of behaviour from transit networks becomes the norm, we
are in big trouble.

William Waites
LFCS, School of Informatics, University of Edinburgh

The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.