CIDR,Sprint and the Big Guys.

Avi Freedman freedman at
Fri Apr 5 15:18:25 UTC 1996

> > From: Jim Fleming <JimFleming at>
> > To: "'Christian Nielsen'" <cnielsen at>, "nanog at"
> > Subject: RE: CIDR,Sprint and the Big Guys.
> > Date: Fri, 5 Apr 1996 01:29:10 -0600
> > 	[...]
> > Yes CIDR is a good thing...unfortunately, it does not guarantee that the
> > net will grow and aggregate in a rational way. When coupled with the
> > "slow start" ISP policy, CIDR helps to rapidly fragment the IP address
> > space and in some cases causes poor IP address utilization all in the
> > name of "protecting the future of the Internet" or maybe "protecting the
> > Internet from ISPs".
> > 	[...]
> It would appear that there may also be a strong argument that the
> tremendous proliferation of [small] ISPs is a significant contributor
> to the growth of the size of the Internet routing tables.
> Perhaps, the [anticipated] consolidation of ISPs will be a significant
> event in the efforts to control routing table size.
> -tjs

Not unless they happen to have contiguous address space.

Seriously, almost every small ISP that I know of gets addresses from its
upstream provider(s).  Therefore, unless they're dual-homed, they don't
contribute to the growth of the size of the tables.

Yes, they may sign up people with IPs in the swamp and route for them,
but so may any other ISP/NSP.

I can't imagine that there are more than 300 local and regional ISPs
that receive address space from the NIC directly.  I could be wrong,
of course...


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