[9983] in North American Network Operators' Group
Re: NSP ... New Information
daemon@ATHENA.MIT.EDU (Paul Ferguson)
Tue Jun 10 11:43:25 1997
Date: Tue, 10 Jun 1997 11:19:50 -0400
To: Phil Howard <phil@charon.milepost.com>
From: Paul Ferguson <pferguso@cisco.com>
Cc: nanog@merit.edu
In-Reply-To: <199706101422.JAA02440@charon.milepost.com>
At 09:22 AM 06/10/97 -0500, Phil Howard wrote:
>
>Right. But people see it as such a problem because the routing policies
>are IP space derived. When people are told they need a /19 to be routable,
>then they begin to go backwards on solving the IP space problem and resume
>wasting it (but hiding the waste to look like its used).
>
But this is somewhat of a misnomer. It is not an issue of being
'routable' v. 'non-routable', but rather, one of whether you can
be aggregated into a larger prefix. This practice encourages
aggregation -- it is commonly agreed that Aggregation is Good (tm).
The routability issue comes into play when:
o You are specifically referring to routes being propagated by
a service provider who uses prefix-length filters, AND
o You cannot be aggregated into a large enough advertised CIDR
block to conform to these types of filters.
>When the need to justify space usage occurred, along with it came some ideas
>on actually how to do that. And I see that working. We were projected to
>run totally out of space by now, and since we have not, I assume it did work
>pretty well.
>
BGP4, CIDR, or Die.
>But the real problem is routing policies that are encouraging people to go
>back to wasting space. By using the network size as the criteria for doing
>route filtering, the smaller guys get screwed and they see their solution
>as inflating their network. This practice needs to be stopped or a better
>solution needs to come out of it.
>
One might suggest that some of the prefix length filter could be
replaced by more aggressive dampening policies.
- paul
