[18816] in North American Network Operators' Group
Re: The Cidr Report
daemon@ATHENA.MIT.EDU (Sean M. Doran)
Tue Aug 18 06:43:23 1998
From: "Sean M. Doran" <smd@clock.org>
To: alex@nac.net, tli@juniper.net
Cc: apops@apnic.net, eof-list@ripe.net, nanog@merit.edu, routing-wg@ripe.net,
tbates@cisco.com
Date: Tue, 18 Aug 1998 03:25:03 -0700
Tli asked:
| Exercise for the reader: If prefixes of length F and longer are filtered,
| and a domain has a prefix of length N, how many prefixes can they propagate
| into the backbone? How many before people start proxy aggregating them?
A/ (2 ** F) - 1. [assuming nobody imposes exact-match prefix filters]
B/ When we can easily do:
"router bgp N
proxy-aggregate route-map Lazy-Types
! exceptions
route-map Lazy-Types deny 10
match as-path 100
! the rule
route-map Lazy-Types permit 20
match originated-prefix-count 16"
then the number 16 strikes me as a starting point,
although I probably want to re-read Dennis's comments
from a few years ago.
Do I pass?
Sean.
