HP-UX Reference (11i v1 00/12) - 1M System Administration Commands N-Z (vol 4)

ManualsBrandsHP ManualsSoftwareHP-UX Reference Manuals

561

562

563

564

565

566

567

568

569

570

__________________________________________________________________________________________________________________________________________________________________________________________________

STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man1m/naaagt.1m

________________________________________________________________

___ ___

xntpd(1M) xntpd(1M)

The ﬁle format is similar to other UNIX conﬁguration ﬁles. Comments begin with a # character and extend

to the end of the line. Blank lines are ignored. Conﬁguration commands consist of an initial keyword fol-

lowed by a list of arguments, some of which may be optional, separated by white space. Commands may not

be continued over multiple lines. Arguments may be host names, host addresses written in numeric,

dotted-quad form, integers, ﬂoating point numbers (when specifying times in seconds) and text strings.

Optional arguments are delimited by []in the following descriptions, while alternatives are separated by

|. The notation [ ... ] means an optional, indeﬁnite repetition of the last item before the [ ... ].

While there is a rich set of options available, the only required option is one or more server, peer or broad-

cast commands described in the "Conﬁguration Options" section. The examples in

/etc/ntp.conf.example may also be helpful.

CONFIGURATION OPTIONS

The conﬁguration commands are as decribed below:

peer address [ key key_id ][version version_id ][ prefer ]

server address [ key key_id ][version version_id ][ prefer ][mode mode ]

broadcast address [ key key_id ][version version_id ][ttl ttl ]

The above three commands can be used to specify either the name or address of the time server and the

mode in which the time server should operate. The address can be either a DNS name or an IP address in

dotted-quad notation.

The peer command speciﬁes that the local server is to operate in symmetric active mode with the remote

server. In this mode, the local server can be synchronized to the remote server and, in addition, the remote

server can be synchronized by the local server. This is useful in a network of servers where, depending on

various failure scenarios, either the local or remote server may be the better source of time.

The server command speciﬁes that the local server is to operate in client mode with the speciﬁed remote

server. In this mode, the local server can be synchronized to the remote server, but the remote server can

never be synchronized to the local server. This is the most common operating mode (by far).

The broadcast command speciﬁes that the local server is to operate in broadcast mode, where the local

server sends periodic broadcast messages to a client population at the broadcast/multicast address speciﬁed.

Ordinarily, this speciﬁcation applies only to the local server operating as a sender; for operation as a broad-

cast client, see the broadcastclient

or multicastclient commands below. In this mode,

address is usually the broadcast address of (one of) the local network(s) or a multicast address assigned to

NTP. The address of 224.0.1.1 is assigned to NTP. This is presently the only address that should be used.

Note that the use of multicast features requires a multicast kernel.

OPTIONS

key key_id All packets sent to the address are to include authentication ﬁelds encrypted using the

speciﬁed key identiﬁer, which is an unsigned 32 bit integer. The default is to not include an

encryption ﬁeld.

version version_id

Speciﬁes the version number to be used for outgoing NTP packets. Versions 1, 2, and 3 are

the choices, with version 3 the default.

prefer Marks the server as preferred. All other things being equal, this host will be chosen for syn-

chronization among a set of correctly operating hosts.

ttl ttl This option is used only with broadcast mode. It speciﬁes the ttl (time-to-live) to use on

multicast packets. Selection of the proper value, which defaults to 127, must be

co-ordinated with the network administrator(s).

broadcastclient [address]

This command directs the local server to listen for broadcast messages at the broadcast

address of the local network. The default address is the subnet address with the host ﬁeld

bits set to ones. Upon hearing a broadcast message for the ﬁrst time, the local server meas-

ures the nominal network delay using a brief client/server exchange with the remote

server, then enters the broadcastclient mode, in which it listens for and synchronizes to

succeeding broadcast messages. Note that, in order to avoid accidental or malicious disrup-

tion in this mode, both the local and remote servers should operate using authentication

and the same trusted key and key identiﬁer.

driftfile driftfile

This command speciﬁes the name of the ﬁle used to record the frequency offset of the local

HP-UX Release 11i: December 2000 − 2 − Section 1M−−1065

___