[7979] in North American Network Operators' Group
Re: The Big Squeeze
daemon@ATHENA.MIT.EDU (Sean Donelan)
Tue Mar 4 00:10:56 1997
Date: Mon, 3 Mar 1997 22:30:51 -0600 (CST)
From: Sean Donelan <SEAN@SDG.DRA.COM>
To: nanog@MERIT.EDU
>Computational power required for a route flap is not the issue here.
>
>Many people have stated that, statistically longer prefixes flap
>more. Unfortunately, they have then said that because of this shorter
>prefixes should have looser dampening parameters put on them, when
>what they really meant was that the longer prefixes should have more
>strict dampening parameters put on them. Yes it is exactly the same
>thing, but it is an important semantic distinction. If a group of
>prefixes categorized by a its length tends to flap more than the
>average, then said group should have more strict dampening parameters
>placed on it.
Statistics are soo much fun.
From a single data point on my router, /24's currently account for 64% of
the routing table entries and for 65% of the flapping prefixes. /16's
account for 12% of the routing table entries, and 10% of the flapping
prefixes. It doesn't appear to me there is a significant difference
between flap behaivor of long prefixes and short prefixes. There are
more long prefixes than short prefixes. But as a group they both tend
to flap the same proportion of 2% of the routes within the group.
--
Sean Donelan, Data Research Associates, Inc, St. Louis, MO
Affiliation given for identification not representation
