North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Multi-6 [WAS: OT - Vint Cerf joins Google]

  • From: Richard A Steenbergen
  • Date: Sun Sep 11 03:54:15 2005

On Sun, Sep 11, 2005 at 06:32:58AM +0200, Mikael Abrahamsson wrote:
> 
> Giving each entity who wants to multihome an AS of their own and own 
> address block, doesn't scale. Think this in the way of each home in the 
> world being multihomed, it just doesn't scale.
> 
> IPv6 solved the addressing problem, not the routing problem, in the 
> current model. Let's try to fix the routing problem NOW instead of 5-10 
> years down the road.

To quote some stats from the latest weekly routing table report to hit 
nanog:

BGP routing table entries examined:                              169983
Total ASes present in the Internet Routing Table:                 20445
Origin-only ASes present in the Internet Routing Table:           17787
Origin ASes announcing only one prefix:                            8431

This says that although there are 170k prefixes on the Internet, there are 
only 20k entities who actually need to announce IP space. There is only 
one explanation for such a large difference (8.5x) between these two 
numbers, namely that people who are announcing IP space need multiple 
blocks in order to accomodate their needs.

Yes there are some people who are doing things like announcing 
discontiguous blocks from the same ASN and relying on the network to get 
bits to the right spot, but the majority of these prefixes are due to IP 
rationing, which forces growth into multiple blocks. By eliminating this, 
the vast majority of users will only need to announce 1 prefix, ever. I 
don't know about you, but I'd be quite happy to get the number of prefixes 
down to ~ 20k and growing at the rate of new ASN allocations. :)

Obviously nothing we currently have is going to scale to handle millions 
of users wanting to multihome their cable modem and their DSL at the 
network level, but at least the current system will keep scaling for quite 
a while.

-- 
Richard A Steenbergen <[email protected]>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)