Re: The Top 20 and some deltas

[Tony Bates <]

 Havard Eidnes <Havard.Eidnes@localhost writes:
  * 
  * I think that this tool will not create aggregates where there exists
  * "holes" in the network numbers which are being routed (at least that was

Correct.

  * what I heard last time; I have not actually used or read the program).
  * Such holes may be there because a site is temporarily unavailable,
  * because the network number hasn't been assigned yet etc.
  * 
  * I have yet to see a tool which beats human knowledge when it comes to
  * determining which ranges can be announced as aggregates, especially when
  * the knowledge of the assignment status for blocks is known.  The output
  * of such a tool should be taken mainly as "advice".
  * 
Definately, this is very much an indicator rather than gospel.

  * I will claim that there is nothing dangerous and certainly very small
  * inconvenience or cost involved in announcing such "holes" as part of a
  * CIDR announcement.  Remember that we do it all the time when it comes to
  * non-assigned subnets of class B networks.  Depending on your routing
  * policy, there may be small complications when a customer moves to
  * another service provider, but we all know that, right?  Add to that that
  * you'll be able to assign new networks to your cursomers and route them
  * without having to modify your external announcements, and you have a
  * nice savings in the form of less work to do.
  * 
Sure but who is advocating not announcing holes. The problem is, is it possible
to ever write a tool to know when an aggregate with holes can be formed or
not ?

  * - Havard

		--T