We hit half-million: The Cidr Report

Tue Apr 29 07:31:31 UTC 2014

On 29 Apr 2014, at 12:39 pm, Valdis.Kletnieks at vt.edu wrote:

> On Mon, 28 Apr 2014 21:59:43 -0400, "Patrick W. Gilmore" said:
>>> On Apr 28, 2014, at 19:41, Chris Boyd <cboyd at gizmopartners.com> wrote:
>>> I'm in the middle of a physical move.  I promise I'll take the 3 deagg'd
>>> /24s out as soon as I can.
>> Do not laugh. If everyone who had 3 de-agg'ed prefixes fixed it, the table
>> would drop precipitously. We all have to do our part.
> 
> Do we have a handle on what percent of the de-aggrs are legitimate attempts
> at TE, and what percent are just whoopsies that should be re-aggregated?
> 

I made a shot at such a number in a presentation to NANOG in Feb this year
(http://www.potaroo.net/presentations/2014-02-09-bgp2013.pdf)

If you assume that Traffic Engineering more specifics share a common origin AS with the
covering aggregate, then around 26% of more specifics are TE advertisements. This 
number (as a percentage) has gwon by 5% over the past three years

If you assume that Hole Punching more specifics are more specifics that use a different
origin AS, then these account for 30% of the more specifics in today's routing table.
This number has fallen by 5% over the past three years.

The remainder of the prefixes (45%) shares the same origin AS and the same path.
The could be TE prefixes, but as they are identical to their covering
aggregate its hard to appreciate exactly what the engineering intent may be. I could
make a wild guess and call these 45% of more specifics to be an act of senseless routing
vandalism. ( :-) ) This number has been steady as a % for the past three years.

Interestingly, it's the hole punching more specifics that are less stable, and the
senseless routing vandalism more specifics that are more stable than the average.

thanks,
   Geoff