[ih] Minutes before Trump left office, millions of the Pentagon's dormant IP addresses sprang to life

[Stephane Bortzmeyer]

On Mon, Apr 26, 2021 at 11:57:08AM -0700,
 Karl Auerbach via Internet-history <internet-history at elists.isoc.org> wrote 
 a message of 35 lines which said:

> If they are advertising this as a single /8 it is unlikely that they will
> catch many folks who are camping on smaller blocks of that space because
> route selection will tend to use the longest match prefix rather the the
> rather short /8 prefix.
> 
> If they really want to sweep the space to locate usurping uses they probably
> need to advertise that /8 as a sequence of /24s.

It's what they do (and it's much more than a single /8). Technical
details:

https://www.kentik.com/blog/the-mystery-of-as8003/

Or in your favorite BGP explorer (I use https://stat.ripe.net/)