ntpdc.8

<B>Digital的Unix操作系统VAX 4.2源码</B>

.TH ntpdc 8
.SH Name
ntpdc \- monitor operation of the NTP daemon, ntpd
.SH Syntax
.B /usr/etc/ntpdc 
[
.B \-n
][
.B \-v
]
\fIhost1 \fR|\fP IPaddress1 ... \fP
.SH Description
The
.PN ntpdc
.NXR "ntpdc command" 
command sends a query to the
.PN ntpd
daemon running on each of the hosts listed on the command line.
The 
.PN ntpd
daemon on each responding host sends information about the
current calculated offset between its time and the time of each of
its NTP servers or peers.  The
.PN ntpdc
command formats the information on the standard output.
.PP
.NT
You can specify hosts by either host name or Internet
address.  The hosts that you specify must either exist
in the
.PN /etc/hosts
file, or in the master
.PN hosts
database, if the database is being served to your
system by BIND/Hesiod or Yellow Pages.
.NE
The 
.PN ntpdc
command by default generates a terse, table-style report.
If you 
specify the 
.PN \-v
option, the 
.PN ntpdc
command generates a verbose report.
.SH Options
.IP \-n
Prints Internet addresses, instead of host names, of the
servers or peers.
By default, the Internet addresses of the responding hosts and the
names of their servers or peers are
printed.  
.IP \-v
Prints a verbose report for each of the servers or peers
of the responding host.
.SH Examples
.SS
Terse Report:
.PP
The following is a typical terse report generated in response to the
command:
.EX
% \f(CB/usr/etc/ntpdc 555.5.55.55
.EE
The host 555.5.55.55 is an NTP client, with the servers
.PN server1 ,
.PN server2 ,
and
.PN server3
specified in its
.PN /etc/ntp.conf
file.  The information returned is about 
.PN server1 ,
.PN server2 ,
and
.PN server3 .
.if t .ig
.ta .5i 1i 2.3i 3.0i 3.5i 4.1i 4.8i 5.6i
	\fBAddress	Strat	Poll	Reach	Delay	Offset	Disp\fP
.br
(rem)	(lcl)
.br
\&.\fIserver1\fP	555.5.55.55	1	64	377	53.0	-65.0	5.0
.br
*\fIserver2\fP	555.5.55.55	1	256	377	155.0	-4.0	16.0
.br
+\fIserver3\fP	555.5.55.55	2	64	377	16.0	-61.0	3.0
..
.if n .ig
.ta .3i .7i 1.7i 2.2i 2.7i 3.2i 3.9i 4.6i
	\fBAddress	Strat	Poll	Reach	Delay	Offset	Disp\fP
.br
\fB(rem)	(lcl)\fP
.br
\&.\fIserver1\fP	555.5.55.55	1	64	377	53.0	-65.0	5.0
.br
*\fIserver2\fP	555.5.55.55	1	256	377	155.0	-4.0	16.0
.br
+\fIserver3\fP	555.5.55.55	2	64	377	16.0	-61.0	3.0
..
.PP
The fields are interpreted as follows:
.IP "\- , + , . \fRor\fP *"
A minus sign (\-), plus sign (+), or dot (.) indicates a 
pre-configured peer (see the
.MS ntp.conf 5
reference page).  The asterisk (*) indicates which pre-configured peer (if
any) is currently being used for synchronization.
.IP (rem)
The remote host name or Internet address of a peer or server of the 
responding host.
.IP (lcl)
The Internet address of the responding host that was specified on the 
.PN ntpdc 
command line.
.IP Strat
The current operating stratum level of the peer 
or server.  Since the NTP hierarchy can change dynamically the stratum
levels may change.  Lower stratum levels correspond to higher accuracy.
.IP Poll
Current polling interval in seconds for this peer or server.
Polling intervals change dynamically.
.IP Reach
Reachability in response to the last 8 polls (value of
8-bit shift register with bits entering from the end furthest to the right).
.IP Delay
The estimated round-trip delay in milliseconds for 
NTP message exchanges between the responding host and this peer
or server.  Delay is calculated from the previous 8 polls.
.IP Offset
The estimated offset between the peer or server's time and the responding
host's time in milliseconds.  This value is calculated from the
previous 8 polls.
.IP Disp
The current estimated value of dispersion in milliseconds for this peer's
offset/delay pair.
.IP
Dispersion is used by the
.PN ntpd
daemon in the clock selection algorithm.  Increasing values of dispersion are
associated with decreasing quality of the estimate.
.SS
Verbose Report:
.PP
When the 
.PN \-v 
option is given, a verbose report for each of the servers or peers
of each of the hosts
specified on the command line is generated.
.PP
The following is a typical verbose report generated in response to the
following command line:
.EX
% \f(CB/usr/etc/ntpdc \-v 111.11.111.11\fP

Neighbor address 555.55.5.55 port:123  local address 111.11.1.11
Reach: 0377 stratum: 2, precision: \-7
dispersion: 2.000000, flags: 1301, leap: 0
Reference clock ID: [22.22.2.22] timestamp: 7e5aa1a9.2add5d0b
hpoll: 10, ppoll: 10, timer: 1024, sent: 85 received: 90
Delay(ms)   20.00  20.00  28.00  29.00  20.00  39.00  29.00  28.00
Offset(ms)   5.00   6.00   5.00  \-1.00  \-2.00   0.00   3.00   5.00

        delay: 20.000000 offset: 5.000000 dsp 2.000000
--------------------------------------------------------------------
.EE
.PP
The fields are interpreted as follows:
.IP "Neighbor address"
The address and port number of one NTP server, followed by
the Internet address of the responding host (\f(CWlocal address\fP).
.IP Reach: 
Reachability in response to the last 8 polls (value of
8-bit shift register with bits entering from the end furthest to the right).
.IP stratum: \fIn\fP
The current operating stratum level of the peer 
or server.  Since the NTP hierarchy can change dynamically the stratum
levels may change.  Lower stratum levels correspond to higher accuracy.
.IP precision: \fInn\fP
The precision of this clock, given in seconds as a power of
2.  If precision is equal to
\-7, that means that the precision is 2**\-7, or 1/128 seconds.
The
.PN ntpd
daemon automatically determines the precision of each clock based on the
kernel variable 
.PN HZ .
.IP disp: \fInn\fP
The current estimated value of dispersion in milliseconds for this peer's
offset/delay pair.
Dispersion is used by the
.PN ntpd
daemon in the clock selection algorithm.  Increasing values of dispersion are
associated with decreasing quality of the estimate.
.IP "flags: \fInn\fP"
The 
.PN flags
parameter is used by the
.PN ntpd
daemon clock selection process.
.IP "leap: \fIflag\fP"
The leap second indicator.  Non-zero if there is to be a
leap second inserted in the NTP timescale.  The bits are
set before 23:59 on the day of insertion and reset after
00:00 on the following day.
.IP "Reference clock ID: \fIaddress\fP"
If the NTP server is synchronized by a radio/satellite
timecode receiver, this field is
.PN WWV ,
.PN WWVB ,
or 
.PN GOES .
If the NTP server is the local reference clock, this field is
.PN LOCL .
Finally, this field can be the
.PN [internet_address]
of the most accurate NTP server currently serving the responding
host.
.IP "timestamp: \fInn\fP"
The local time, in hex-timestamp format, when the local clock
of the server was last updated.
.IP "hpoll: \fIn\fP"
The host poll interval which is the maximum interval between messages
transmitted to the server, in seconds as a power of 2.  For
example, a value of 6 indicates an interval of 64 seconds.
.IP "ppoll: \fIn\fP"
The peer poll interval which is the maximum interval between messages
sent by the server, in seconds as a power of 2.  For
example, a value of 6 indicates an interval of 64 seconds.
.IP "timer: \fInn\fP"
The current poll rate in seconds.
.IP "sent: \fInn\fP"
The number of NTP packets sent to this server by the responding host.
.IP "received: \fInn\fP"
The number of NTP packets received from this server by the responding
host.
.IP "Delay and Offset"
The round-trip delay and estimated clock offset for the last eight NTP
packet exchanges.  If there are fewer than eight valid samples,
the delay field will be zero.
.IP "delay: \fIest-delay\fP offset: \fIest-offset\fP dsp: \fIn\fP"
Estimated delay, offset, and dispersion calculated from the
above 8 samples.  See RFC 1129 for how to calculate the 
estimated delay, offset, and dispersion.
.SH Diagnostics
.B "host1: connection refused"
.br
Check whether the 
.PN ntpd
daemon is running on 
.PN host1 .
.PP
.B "host2: unknown"
.br
The 
.PN ntpdc
command cannot resolve the host name
.PN host2 .
Check that 
.PN host2 
exists in the 
.PN /etc/hosts 
file, or that it exists in the master
.PN hosts
database, if the database is being served by BIND/Hesiod or Yellow Pages.
.PP
If a server is listed in the host's
.PN /etc/ntp.conf
file, but does not appear in the 
.PN ntpdc
report, it is possible that the 
.PN ntpd
daemon on the responding host can not resolve the server
names in the
.PN /etc/ntp.conf
file.  Check that the server exists in the responding host's
.PN /etc/hosts
file or in the master
.PN hosts
database, if the database is being served 
to the responding host by BIND/Hesiod or Yellow Pages.
.SH See Also
ntp.conf(5), ntp(8), ntpd(8)
.br
\fIRFC 1129\(emInternet Time Synchronization:  the Network Time Protocol\fP
.br
.I "Introduction to Networking and Distributed System Services"