Configuring a Simple NTP CLIENT:
The first section is concerned with configuring an NTP client.
ie. a client obtaining it's time from another local Unix or Windows
or Linux Master Time Server either within the Intranet or, if
available, the Internet.
1. Verify that you are able to ping xxx.xxx.xxx.xxx, where this is
your Master Time Server.
2. Synchronize the clocks manually with the following command:
# ntpdate -v -b xxx.xxx.xxx.xxx
or use the additional options:
-d debug
-s write the information into syslog rather than console
-o 3 specify the ntp version (default is 3)
Use "ntpdate" to ensure that the clocks are synchronised before
the "ntp" daemon starts and it is often found that no further
"ntp" configuration is done other than to add this command to the
cron and run on a regular basis.
This feature cannot be used if a "ntpd" daemon is already running
on this client as they share the same port and you will see the
error:
"the NTP socket is in use, exiting"
If you see:
"no suitable server for synchronization found"
then it's likely the server you are communicating with is not
a Master Time Server and is not advertising the time.
Running ntpdate also resets the System Clock and server's RTC.
As an alternate to using NTP, ntpdate can be placed in the cron
to be run on an hourly basis, for example:
59 * * * * /etc/ntpdate -v my_time_server >> /var/log/ntp.log
2>&1
3. Configure the file ntp.conf as:
broadcastclient no
driftfile /etc/ntp.drift
logfile /var/log/ntp.log
server xxx.xxx.xxx.xxx
server ...
where "xxx.xxx.xxx.xxx" is the IP address of the Master Time
Server you wish to use.
How to configure it?
You should use the "scoadmin client" or use the SCOadmin Client
Manager from the GUI to set it where the operating system is
either UnixWare 7.x.x, Open UNIX 8.0.x or OpenServer 5.0.x/6.0.0.
For OpenLinux, use the KDE K-> Control Center-> System->
Startup-> Services-> Network Time Protocol Daemon.
Next, use your favourite text editor to ensure it reads as above.
Please note, ntp will loose it's synchronisation if the time
varies by more than 128ms.
Where is ntp.conf?
ntp.conf is stored in /etc for SCO OpenServer5 and SCO
OpenLinux, and is stored in /etc/inet for UnixWare 7.x.x,
Open UNIX 8.0.x and OpenServer6, however, on OSR6 it is linked to
/etc/ntp.conf.
For UnixWare7 it is recommended to change the driftfile location
to:
driftfile /etc/inet/ntp.drift
The configured drift file is created after the next reboot if
needed.
# touch /etc/inet/ntp.drift
# chmod 666 /etc/inet/ntp.drift
4. Stop and start your server's TCP/IP or simply reboot your server
and the "ntpd" daemon will be started if it finds the above file,
"ntp.conf" has been configured.
Verify that the daemon has been started with:
# ps -ef | grep ntp
ntp by definition does not work with time differences larger than
1000 secs. In that case it stops and tells you to set the system
time manually. (xntpd logs into /var/adm/syslog)
OpenServer starts the "ntp" daemon from /etc/tcp.
UnixWare starts the "ntp" daemon from /etc/inet/config.
5. You can use the "ntpq -p" command in order to check, whether ntp
has started ok.
Please note, that a drift of more than 1000 seconds will not be
corrected from ntp, by default.
You can now monitor the system time by entering the date command
(without any options) from time to time.
Please note that it will take some time (10 to 30 mins) until NTP
corrects the system time.
Configuring a simple NTP SERVER:
===============================
This next section looks at setting up your SCO server as a Master
Time Server.
1. To do this change your "ntp.conf" file to read:
driftfile /etc/ntp.drift (or /etc/inet/ntp.drift for UW7.x.x)
broadcastclient no
server 127.127.1.1
2. Restart your TCP/IP services or reboot your server.
3. Check the service has started with "ps -ef | grep ntp", as above,
and running "ntpq -p".
You will not be able to "ping 127.127.1.1" but this is the entry to
use to tell "ntp" it is the Master Time Server.
Your NTP clients can then be pointed to this server.
NOTES:
TROUBLESHOOTING:
===============
Check the port 123 is opened with "netstat -an" and run:
# ntpq
ntpq> peers
remote refid st t when poll reach delay offset jitter
==============================================================================
*LOCAL(0) LOCAL(0) 7 l 46 64 377 0.000 0.000 0.000
xxx.xxx.xxx.255 0.0.0.0 16 u - 64 0 0.000 0.000 4000.00
On the Client:
ntpq> peers
remote refid st t when poll reach delay offset disp
==============================================================================
LOCAL(0) LOCAL(0) 7 l 13 64 377 0.00 0.000 10.01
*my_time_server. LOCAL(0) 8 u 44 64 377 0.76 0.134 0.05
or:
# ntpq -p
and:
On the Server:
#ntpq
ntpq> as
ind assID status conf reach auth condition last_event cnt
===========================================================
1 39588 8000 yes yes none reject
2 39589 8000 yes yes none reject
3 39590 9614 yes yes none sys.peer reachable 1
ntpq> rv <assID>
On the Client:
ntpq> as
ind assID status conf reach auth condition last_event cnt
===========================================================
1 32724 9614 yes yes none sys.peer reachable 1
2 32725 9014 yes yes none reject reachable 1
ntpq> rv <assID>
and:
You can set debugging from ntpq:
ntpq> debug more
debug level set to 1
ntpq> debug more
debug level set to 2
ntpq> debug more
debug level set to 3
ntpq> peers
Sending 12 octets
select() returns 1
Packet shows signs of authentication (total 20, data 24, mac -4) 18349014
18359634 90f2ab2a 3a010000 5f646e73 7268ad2a Authenticated with keyid 973144064
We don't know that key Got packet, size = 20 Packet okay
remote refid st t when poll reach delay offset disp
==============================================================================
Sending 12 octets
select() returns 1
Packet shows signs of authentication (total 476, data 480, mac -4) 2e30302c
0d0a0000 00000000 01000000 78fc0508 b4d7bd2a Authenticated with keyid 16777216
We don't know that key Got packet, size = 476 Packet okay
select() returns 1
Got packet, size = 168
Packet okay
LOCAL(0) LOCAL(0) 7 l 55 64 377 0.00 0.000 10.01
Sending 12 octets
select() returns 1
Got packet, size = 408
Packet okay
select() returns 1
Packet shows signs of authentication (total 244, data 248, mac -4) 362e3835
0d0a0000 3d302e30 322c2072 65616368 3d307866 Authenticated with keyid 841752690
We don't know that key Got packet, size = 244 Packet okay
*my_time_server. LOCAL(0) 8 u 22 64 377 0.69 0.126 0.02
SEE ALSO:
For UnixWare 7.x.x/Open UNIX 8.0.x/OpenServer6:
in.xntpd (1Mtcp) - Network Time Protocol daemon
xntpd (1Mtcp) - Network Time Protocol daemon
ntpdate (1Mtcp)
For SCO OpenServer 5.0.x:
ntpdate(ADMN)
ntpd(ADMN)
For SCO OpenLinux 3.x:
/usr/share/doc/packages/xntp-4.0.99k/html/ntpdate.htm
http://www.linuxdoc.org/HOWTO/Belgian-HOWTO/configuration.html
which suggests:
To change the CMOS clock and then synchronize the system time with
the CMOS clock, do something like this:
hwclock --set --date="Feb 25 03:38"
clock -u -s
If your computer has Internet access, you can use NTP (Network
Time Protocol) to keep your system clock in sync using the "ntp"
daemon. However, one way of doing this is manually is by starting
"ntpdate" from cron by adding:
05 0 * * * root /usr/sbin/ntpdate -s uk.pool.ntp.org > /dev/null 2>&1
which syncs the clock to the NTP time server ntp.belnet.be.
For a list of public NTP servers, see
http://support.ntp.org/bin/view/Servers/NTPPoolServers
http://support.ntp.org/bin/view/Servers/WebHome#Browsing_the_Lists
The NTP home page is at:
http://www.ntp.org
For example,
uk.pool.ntp.org is a UK NTP server.
Technical Article 107619, "How do I configure xntpd(ADMN) to alter timekeeping
limitations?"
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