20402 routing entries

Mark S. Fedor fedor at msf.psi.net
Fri Apr 15 20:57:04 UTC 1994

I'm sure that we will all eventually do CIDR/BGP4 and maybe even
slow the growth of routing tables to a managable level.  By this
time we will all have 500MB routers.....

Now with talk of global renumbering and a Utopian world of CIDR, what
do we lose?  I was never optimistic of how CIDR would work in a real
operational redundant topology like the current internet.  In this
scenario, it is a big win to be able to have fine grain control of
routing down to the organizational level.

What does this mean?  Well you can develop a routing strategies which
take into account many diverse exit points from your AS.  You can
develop routing strategies based on high end users, low-end users,
route the east coast here, the west coast there.  You name it.

You can't do this by routing large blocks of networks around.

Pure CIDR'ists will say that you should divy up your blocks and assign
addresses accordingly.

Well... how many people who run networks have stayed with the exact
same routing strategy with zero changes for more than 6 months?

New connections and connectivity happen.  The internet is an ever changing
place.  My CIDR allocation today will not be good for my routing strategy
2 months from now.

As Andrew said, we are not fortune tellers...

So, In a totally static topology, CIDR "the movie" and global renumbering
will work.

I wouldn't bet on static topology...


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