[92801] in North American Network Operators' Group
Aggregation & path information [was: 200K prefixes - Weekly Routing Table Report]
daemon@ATHENA.MIT.EDU (Patrick W. Gilmore)
Fri Oct 13 15:18:20 2006
In-Reply-To: <452FE332.5000004@cisco.com>
Cc: "Patrick W. Gilmore" <patrick@ianai.net>
From: "Patrick W. Gilmore" <patrick@ianai.net>
Date: Fri, 13 Oct 2006 15:14:38 -0400
To: nanog@nanog.org
Errors-To: owner-nanog@merit.edu
On Oct 13, 2006, at 3:04 PM, Philip Smith wrote:
> I was kinda hoping that it would hit 200K on Tuesday, then I could
> have
> added the announcement to my aggregation recommendations lightning
> talk!
> ;-) Bit sad that a 200K table can be aggregated down to 109k prefixes
> with no loss of path information (in my BGP table view).
I find this interesting.
Obviously the table contains kruft. But I know we could not shrink
it to 109K prefixes without losing something from where I sit. Are
you sure there's no additional path info?
If there were a way to guarantee certain prefixes are completely
superfluous, we could make a hit list of just those providers, then
ridicule or filter or cause them pain in some way to make them stop
causing us pain. I haven't seen that type of report posted publicly,
just "this CIDR can fit in that one" without actual guarantees that
_paths_ are equivalent. (Usually the origin AS is matched as well as
the prefixes, but that's not the same as guaranteeing the path is
equivalent.)
Of course, this is non-trivial. But then neither is aggregating the
global table. :)
--
TTFN,
patrick
