diff --git a/usr.sbin/ntp/ntpd/ntp.conf b/usr.sbin/ntp/ntpd/ntp.conf
--- a/usr.sbin/ntp/ntpd/ntp.conf
+++ b/usr.sbin/ntp/ntpd/ntp.conf
@@ -29,7 +29,13 @@
 #
 # The option `iburst' is used for faster initial synchronization.
 #
-pool 0.freebsd.pool.ntp.org iburst
+# Use one of the following for IPv4-only time sources:
+# pool 0.freebsd.pool.ntp.org iburst
+# pool 1.freebsd.pool.ntp.org iburst
+# pool 3.freebsd.pool.ntp.org iburst
+#
+# Use the following for IPv4 and/or IPv6 time sources:
+pool 2.freebsd.pool.ntp.org iburst
 
 #
 # If you want to pick yourself which country's public NTP server