nanog mailing list archives

RE: CIDR Report


From: "Daniel L. Golding" <dan () netrail net>
Date: Sun, 14 May 2000 14:35:27 -0400 (EDT)


Of couse, folks have to decide what's important:

1) Routing Table size
        Is this as important of an issue as it was 3 years ago? Nope, not
with M40s and GSRs as standard backbone routes. 100K routes is no sweat
with these boxes. Of course, some of the big carriers would have to
finally replace some of those older 7505s floating around their networks. 

2) IP Address Space Scarcity
        There is no real address space scarcity. We still have most of
64/2 to go through. And there is always an easy answer to this "problem" -
turn IP space into a commodity and have an exchange system where folks
purchased address space from each other. This would result in the hoarded
"class A" space being thrown back into circulation, as the companies that
had them would have an incentive to unload them - money. As IP space is
really not that scarce (and would be less so with the Class A's in
circulation), the prices would be reasonable. When they became
unreasonable, there would be a market-driven move to IPv6. Ah, capitalism.

The answer to most of these issues is to allow much smaller allocations in
a specific block - say 65/8. Allow /24-/21 allocations in this block for
smaller multihomed enterprises. Then, start cracking down on the other
blocks by filtering smaller prefixes. This would enforce necessary
aggregation where possible, but still allow multihomed enterprises to
obtain an appropriate amount of IP space on their own.

As far as routing table growth - with current practices, we will continue
to see this level of growth due to an increase in the number of multihomed
enterpises. How mane non-ISPs ran BGP with upstream providers a few years
ago? How many do now? The growth is astonishing...

Daniel Golding
Director, Network Evaluation and Design
NetRail, Inc.

On Sat, 13 May 2000, Roeland Meyer (E-mail) wrote:


I've mentioned this before, so I'll just note it lightly.
There are a growing number of companies (dot-coms are only one of them) that have small head-count (<4000), but are 
spread out from Sydney to New York, with many "lone eagles" in the MST zone. They could probably do everything on a 
portable /24. However, with everyone filtering out announcements less than /20, such companies are encouraged to drop 
NAT, and use other methods to justify a /19, just so they can participate in peering (I won't say whom, one is a CTI 
development company). The VPN solution is cute, but the entire VP then becomes single-homed, at the VPN gateway (The 
alternative is that each location gets their own /24, linked by a VPN, to the other /24s, there are serious 
performance issues with this approach and hte /24 may only represent a single actual user). All of this burns IP 
addresses. 

The point: Filtering BGP announcements costs in IP space allocations. There is a mathmatical relationship between IP 
address allocations, table sizes, and routing policies. Also, part of the relationship is determined by client 
business requirements.

Organizations are becomeing more geophysically diffused, with many end-nodes actually participating in multiple 
organizations. This is only starting now (I still see over 100K nodes actually doing this), it will get much worse.

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of
Mikael Abrahamsson
Sent: Saturday, May 13, 2000 2:10 AM
To: nanog () nanog org
Subject: Re: CIDR Report



On Sat, 13 May 2000 pjnesser () Nesser COM wrote:

But if you look at the last 250 days or so you see that the 
table has
grown by more than 16k routes.  So we are seeing growth at 
300% of what we
saw for the last 5 plus years.  It also looks annoyingly 
geometric or
perhaps exponential, instead of the nice linear growth 
since CIDR was
introduced.  

If you just check from 01/01/99 to date then it looks linear 
or at least
close to linear.
 
I guess it *could* be that growing amount of new companies getting
internet access is increasing. Is there any data that show "CIDR GAIN"
from the cidr report, so we can see if the increase corresponds to an
increase in (perhaps unneccessary) smaller announcements in 
larger blocks,
or if it is actually just a lot more blocks allocated that needs to be
routed. Any stats on arin/ripe/apnic new allocations of 
blocks in the same
timeframe? Both in terms of IP adresses and in number of blocks of IP
adresses. This would also give us some kind of hint as to 
when IPv4 space
will be exhausted (or are there already projections about this?)

-- 
Mikael Abrahamsson    email: swmike () swm pp se







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