nanog mailing list archives
RE: CIDR Report
From: owen () dixon delong sj ca us (Owen DeLong)
Date: Sat, 13 May 2000 11:06:57 -0700
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.
Or you build a VPN with multiple gateways, and accept the consequences when a gateway drops and you are rerouted to another gateway. This is usually rare, and most users will retry their HTTP request or other session at least once before calling for assistance. It's not pretty, but it is feasible. (Each gateway has it's own NAT pool that it exchanges with the world. Each office on the VPN is dynamically routed to the closest gateway.)
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.
Yes, that is true. I think the long term solution is bigger routing tables with faster lookups and longer prefixes. CIDR was a hack to get us through a time when router memory and speed constraints were creating serious problems in routing the global internet. I believe this problem is mostly solved, and that modern routers are capable of handling a much larger routing table. As such, I think the need for optimization has shifted to IP space utilization and topological efficiency. Deaggregating routes to be able to use effective MEDs would also benefit from this going forward. I know this doesn't fit with Randy's religion, but it's not the first time I have disagreed with Randy. Owen
-----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 thetable hasgrown by more than 16k routes. So we are seeing growth at300% of what wesaw for the last 5 plus years. It also looks annoyinglygeometric orperhaps exponential, instead of the nice linear growthsince CIDR wasintroduced.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
Current thread:
- CIDR Report pjnesser (May 13)
- Re: CIDR Report Mikael Abrahamsson (May 13)
- RE: CIDR Report Roeland Meyer (E-mail) (May 13)
- RE: CIDR Report Daniel L. Golding (May 14)
- Multi-home I (was CIDR Report) Rural CNE (May 13)
- RE: CIDR Report Roeland Meyer (E-mail) (May 13)
- Re: CIDR Report Christian Nielsen (May 13)
- Re: CIDR Report Vijay Gill (May 13)
- Re: CIDR Report Mark Kent (May 13)
- Re: CIDR Report Geoff Huston (May 13)
- Re: CIDR Report Jeremy Porter (May 14)
- <Possible follow-ups>
- RE: CIDR Report Owen DeLong (May 13)
- Re: CIDR Report Danny McPherson (May 13)
- RE: CIDR Report Roeland Meyer (E-mail) (May 13)
- Re: CIDR Report Randy Bush (May 13)
- Re: CIDR Report Danny McPherson (May 13)
- RE: CIDR Report Roeland M.J. Meyer (May 13)
- Re: CIDR Report ww (May 13)
- Re: CIDR Report Joe Provo - Network Architect (May 14)
- Re: CIDR Report Chris Williams (May 15)
- Re: CIDR Report Adrian Chadd (May 15)
- Re: CIDR Report Chris Williams (May 15)
- RE: CIDR Report Roeland M.J. Meyer (May 13)
- Re: CIDR Report Mikael Abrahamsson (May 13)