Randomness could be a natural outcome if the default configuration for SOHO routers was to create one and bury the ability to specify it under some 'Advanced/Experts-only' option. There is a 'need' for this space to satisfy Enterprise network managers that have external partnerships and are unwilling to deal with collisions no matter how unlikely. While these organizations could use their PI space for this, they don't want to because that ends up impacting their internal routing due to the number of deaggregates that get announced. Tony
-----Original Message----- From: address-policy-wg-admin@ripe.net [mailto:address-policy-wg- admin@ripe.net] On Behalf Of Jeroen Massar Sent: Friday, May 04, 2007 10:17 PM To: Vince Fuller Cc: address-policy-wg@ripe.net Subject: Re: [address-policy-wg] 2007-05 New Policy Proposal (IPv6 ULA- Central)
Vince Fuller wrote:
The general solution of the probability of a collision after d draws from n possible values is given by:
P = 1 - ((n!) / ((n**d)((n-d)!)))
Given that the value for n is 2.199,023,255,552, then the objective is to find the lowest value of d for which P is greater than or equal to 0.5. In this case the value for d is some 1.24 million.
Are people going to pick random values? I'd expect a more likely outcome to be that they will pick strings that are easy to remember. How many collisions will there be if that is the case? Remember DEADBEEF?
If one is doing that, then why even bother using ULA's. Just use 1234::/48 or something similar then ;)
One can't engineer around stupid people unfortunately...
Greets, Jeroen