ntp config tech note

Fri May 21 01:18:10 UTC 2004

On Thu, 20 May 2004 17:33:22 -0400
Jared Mauch <jared at puck.nether.net> wrote:

> 	I'm also wondering, how many people are using the ntp.mcast.net
> messages to sync their clocks?  what about providing ntp

We have had one user that I know of who was receiving time sync info
via multicast announcements, but personally I don't care for doing NTP
this way.  In my experience systems/users don't bother to do any sort
of authentication or filtering on NTP sources.  Most server admins and
some implementations do not support authentication either.  I'm pretty
sure I don't want to get time from just anyone who sends to 224.0.1.1
especially on networks connected to the multicast-enabled Internet.
That group address I might note is one I tend to scope at admin
boundaries for just that reason.

John