[ntpwg] draft-gayraud-dhcpv6-ntp-opt-01.txt

[Bernie Volz (volz)]

In addition after attending today's NTP session, I think you'd be far
better to:

1. Make use of the existing OPTION_SNTP_SERVERS (RFC4075) but request
that IANA rename this to OPTION_NTP_SERVERS and explain why (that SNTP
refers to a client implementation, not the server and thus it should be
NTP_SERVERS which can be used by either NTP or SNTP clients).

Note: As the option usage is not changing, this is the correct to do. It
would be a very bad idea to request a new option because then many
servers will need to have both the OPTION_SNTP_SERVERS and the new
option configured with the same list of servers which is kind of
useless.

2. Define a new OPTION_NTP_DOMAIN_NAME option that is used to specify
the domain name of an NTP server. You can allow multiple of these
options if the ability to provide multiple domain names is desired. See
RFC 3898 which defines the NIS/NISP "servers" and "domain name" options.

- Bernie

-----Original Message-----
From: Bernie Volz (volz) 
Sent: Wednesday, March 12, 2008 2:20 PM
To: Benoit Lourdelet (blourdel); 'ntpwg at lists.ntp.isc.org'
Cc: DHC WG
Subject: draft-gayraud-dhcpv6-ntp-opt-01.txt

One issue in draft-gayraud-dhcpv6-ntp-opt-01.txt is that the
NTP_SUBOPTION_SRV_FQDN suboption "fqdn" data must be DNS wire encoded as
described in RFC 3315, Section 8 (Representation and Use of Domain
Names).

Thus:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    NTP_SUBOPTION_SRV_FQDN     |        suboption-len = 15     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      'n'      |      't'      |      'p'      |      '.'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      'e'      |      'x'      |      'a'      |      'm'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      'p'      |      'l'      |      'e'      |      '.'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      'c'      |      'o'      |      'm'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       sub-option-code: NTP_SUBOPTION_SRV_FQDN  (2)

       sub-option-len:  length of the included FQDN (15) 
 
Would actually be:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    NTP_SUBOPTION_SRV_FQDN     |        suboption-len = 17     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       3       |      'n'      |      't'      |      'p'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       7       |      'e'      |      'x'      |      'a'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      'm'      |      'p'      |      'l'      |      'e'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       3       |      'c'      |      'o'      |      'm'      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       0       |
     +-+-+-+-+-+-+-+-+

       sub-option-code: NTP_SUBOPTION_SRV_FQDN  (2)

       sub-option-len:  length of the included FQDN (17)

Also, usually DHCP option definitions just define the option format
without giving a specific example.

- Bernie