The Big Squeeze

Erik Sherk sherk at
Mon Mar 3 14:05:17 UTC 1997

> > When dampening was first being rolled out I remember one of the early
> > networks that got hit was PSI's net 38/8.  Treating flapping prefixes
> > differently based on length has more to do with how many people scream
> > when prefixes covering a large amount of address space get dampened
> > than the impact of the route flap of an individual prefix on the router.
> Also, it is thought that longer prefixes tend to flap more than shorter.
> randy

Sean has a good point here. A flap of a /8 is the same as a flap of a /24
from a computational point of view. There is clearly some social engineering
going on here. If you want your long prefix to be golbally visable and you
allow it to flap, then you will be subject to dampening. On the other hand
if you renumber into a larger aggregate, then you are protected from dampening 
(to a greater degree). Kind of a 'carrot and stick' approch. :-)


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