On Feb 3, 2014, at 3:29 PM, John R. Levine <jo...@iecc.com> wrote: >>> It seems thata hosts sending large amounts of NTP traffic over the >>> public Internet can be safely filtered if you don't already know that >>> it's one of the handful that's in the ntp.org pools or another well >>> known NTP master. >> >> Speaking as one of the 3841 servers in the pool.ntp.org pool, I'm happy to >> be described as a "handful," something my mother used to say, but I do feel >> obligated to point out that it's a pretty big handful especially if you want >> to be fiddling ACLs on an hourly basis which is pretty much what it takes. > > I was thinking that the ntp.org servers on any particular network are a small > set of exceptions to a general rule to rate limit outgoing NTP traffic.
www.pool.ntp.org allows any NTP operator to opt-in to receive NTP traffic should their clock be available and accurate. - Jared
