Stale NTP software included in FreeBSD (RELEASE/STABLE/CURRENT)

[David Magda]

On Sep 4, 2014, at 13:17, dweimer <dweimer at dweimer.net> wrote:

> You can add this to rc.conf, if I am not mistaken, and it will do the same thing for ntpd
> ntpd_flags="-I 192.168.1.2"
> 
> Probably not quite as clean as adding it to the configuration file, but gets the job done.

From the 4.2.6 ntpd(1) man page on Mac OS X:

       -I iface, --interface=iface
              Listen  on an interface name or address.  This option may appear
              an unlimited number of times.

              Open the network address given, or all the addresses  associated
              with  the given interface name.  This option may appear multiple
              times.  This option also implies not  opening  other  addresses,
              except  wildcard  and  localhost.   This  option  is deprecated.
              Please consider using the configuration file interface  command,
              which is more versatile.

And for ntp.conf:

> interface [listen | ignore | drop] [all | ipv4 | ipv6 | wildcard | name | address[/prefixlen]]
> 
> This command controls which network addresses ntpd opens, and whether input is dropped without processing. The first parameter determines the action for addresses which match the second parameter. That parameter specifies a class of addresses, or a specific interface name, or an address. In the address case, prefixlen determines how many bits must match for this rule to apply. ignoreprevents opening matching addresses, drop causes ntpd to open the address and drop all received packets without examination. Multipleinterface commands can be used. The last rule which matches a particular address determines the action for it. interface commands are disabled if any -I, --interface, -L, or --novirtualips command-line options are used. If none of those options are used and nointerface actions are specified in the configuration file, all available network addresses are opened. The nic command is an alias forinterface.

	http://www.eecis.udel.edu/~mills/ntp/html/miscopt.html#interface

So be mindful about that option if you every upgrade.