[ntp:questions] NTP over redundant peer links, undetected loops

Joseph Gwinn joegwinn at comcast.net
Sun Feb 15 20:09:37 UTC 2009

In article 
<5d7f07420902151105m48a5e210s72e8e168e67d17a2 at mail.gmail.com>,
 malayter at gmail.com (Ryan Malayter) wrote:

> On Sun, Feb 15, 2009 at 12:23 PM, Danny Mayer <mayer at ntp.org> wrote:
> >
> > Because I want to get away from the notion that these are meant to be IP
> > addresses. In addition in an IPv6-only environment that wouldn't work
> > either. Why create work when it's unnecessary just to find a valid IP
> > address? In addition with anycast addresses are not globally unique. The
> > chances that you will create a non-unique random number within a network
> > is extremely low.
> It depends on the size of the network. The chances of a duplicate
> 32-bit number on a network including 65000 hosts is about 40%. The NTP
> Pool network, which comprises at least 10^6 hosts, for example, would
> have collision probability very close to 1.

How did you compute that?  Given that 2^32= ~4*10^9, it's hard to see 
how 10^6 hosts spread at random in a 10^9 codespace could achieve 100% 
collision probability.

Joe Gwinn

More information about the questions mailing list