Update ntp.conf to use the ntpd pool feature.


Update ntp.conf to use the ntpd pool feature.

Our previous ntp.conf file configured 3 servers from freebsd.pool.ntp.org
using 3 separate 'server' config lines. That is now replaced with a single
'pool' line which causes ntpd to add multiple servers from the pool.

More than just making the config smaller, the pool feature in ntpd has one
major advantage over configuring 3 separate servers from a pool: if a server
that was added using a 'pool' statement provides bad time (initially or at
some later date), ntpd automatically discards it and configures a new
different server from the pool without needing to be restarted.

These changes also add a 'tos' line to control how many pool servers get
added, a 'restrict source' line that is required to allow ntpd to add new
peers from the pool, and it deletes a 'restrict' line that does
nothing and should never have been there ( is not a valid IP
address, it's a refclock identifier).

Differential Revision: https://reviews.freebsd.org/D9011


ianJan 2 2017, 3:19 PM
Differential Revision
D9011: Modernize ntp.conf to use the ntpd pool feature.
rS311102: Cleanup inelegant calloc(3) introduced in r310984.