The Cidr Report

This is an auto-generated mail on Fri Jun 25 12:00:00 PDT 1999
It is not checked before it leaves my workstation. However, hopefully
you will find this report interesting and will take the time to look
through this to see if you can improve the amount of aggregation you

The report is split into sections:

   0) General Status
      List the route table history for the last week, list any possibly
      bogus routes seen and give some status on ASes.

   1) Gains by aggregating at the origin AS level

      This lists the "Top 30" players who if they decided to aggregate
      their announced classful prefixes at the origin AS level could
      make a significant difference in the reduction of the current
      size of the Internet routing table. This calculation does not
      take into account the inclusion of holes when forming an aggregate
      so it is possible even larger reduction should be possible.

   2) Weekly Delta

      A summary of the last weeks changes in terms of withdrawn and
      added routes. Please note that this is only a snapshot but does
      give some indication of ASes participating in CIDR. Clearly,
      it is generally a good thing to see a large amont of withdrawls.

   3) Interesting aggregates

      Interesting here means not an aggregate made as a set of
      classful routes.

Thanks to for giving me access to their routing tables once a

Please send any comments about this report directly to me.

Check for a daily
update of this report.

On the subject of the general number of routes increasing, has
everyone involved in the development or maintainence of their routers
checked that the 2^16 (65536) limit is not going to hit them.

I know that for those using PC routers, like my old colleagues at
Demon, it is important that you make sure that your OS is upgraded
to use a >16 bit int for a "reference count" to an interface. Andrew
Bangs @ Demon spotted this a while back and submitted patch to the
*BSD groups, of which I know OpenBSD has changed the reference count
to a 32 bit.

Once you add some IGP routes the 2^16 is coming up fast.