Bug 216079

Summary: NTPD(8) interface command undocumented
Product: Documentation Reporter: Jason Mader <jasonmader>
Component: Manual PagesAssignee: freebsd-bugs (Nobody) <bugs>
Status: New ---    
Severity: Affects Only Me CC: diego.casati, doc
Priority: --- Keywords: patch
Version: Latest   
Hardware: Any   
OS: Any   
Description Flags
wrong diff. please ignore
add information on interfaces to the ntp.conf.5 none

Description Jason Mader 2017-01-14 16:38:30 UTC
In the ntpd man page, this is mentioned,

This option is deprecated. Please consider using the configuration file
interface command, which is more versatile.

Except there is no mention of the interface command in NTP_CONF(5)

from the NTP software website it would be,

interface [listen | ignore | drop] [all | ipv4 | ipv6 | wildcard | name | address[/prefixlen]]
Comment 1 Diego Casati 2017-01-16 18:31:59 UTC
Created attachment 178965 [details]
wrong diff. please ignore

Adds THR as a consulting service in North America. 

@THR - Does this look correct for you ?

Comment 2 Diego Casati 2017-01-16 18:53:54 UTC
Comment on attachment 178965 [details]
wrong diff. please ignore

wrong diff. please ignore
Comment 3 Diego Casati 2017-01-16 21:23:34 UTC
I believe we pull the code from ntp.org. After checking their code, this bit of information is present there either. 

For that, I'll file a bug report with them.

Meanwhile, this is what you're looking for:

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. ignore prevents opening matching addresses, drop causes ntpd to open the address and drop all received packets without examination. Multiple interface 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 no interface actions are specified in the configuration file, all available network addresses are opened. The nic command is an alias for interface.

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

I am also attaching a patch here in case the FreeBSD dev wants to include it.
Comment 4 Diego Casati 2017-01-16 21:24:49 UTC
Created attachment 178971 [details]
add information on interfaces to the ntp.conf.5

add the undocumented option of using interface
Comment 5 Diego Casati 2017-01-18 02:36:05 UTC
Created a bug report with ntp.org: http://bugs.ntp.org/show_bug.cgi?id=3368