How do I set time with ntp?

kakabaratruskia · 2003-09-24 22:39:11

I've just edited my /etc/ntp.conf, and it's now like this:

restrict default noquery notrust nomodify
restrict 127.0.0.1
restrict 200.30.227.0 mask 255.255.255.0
fudge 127.127.1.0 stratum 3
server ntp.shoa.cl
server ntp.dgf.uchile.cl
driftfile /etc/ntp.drift
logfile /var/log/ntp.log

Now, when I do /etc/rc.d/ntpd start the time doesn't change (it's wrong now). I don't know what do I have to do. I've read the documentation, but didn't got it, cause it was in english, and I'm not fluid in it.

contrasutra · 2003-09-24 22:53:12

I run this in my rc.local:

ntpdate 208.184.49.9

Every startup it adjusts my time.

You'll have to find a time server near you though, this one is NJ.

kakabaratruskia · 2003-09-24 23:25:45

then what is for ntpd?

contrasutra · 2003-09-25 00:26:11

Its used for updating it automatically at certain times.

I would use a CRON job, but thats just me. I dont want any more daemons running than I have to.

andy · 2003-09-25 07:02:46

ntpd GRADUALLY changes the time. It slows down or speeds up the system clock just a bit until the system clock corresponds to what the ntp servers report. If you are online a lot then ntpd is the preferred way of setting the time. The network overhead is really small and the system doesn't really notice any "fractures in the time continuum" ;-) ...
So, your ntp.conf file looks about right. You just need to wait a while (30 minutes to an hour to be safe) to see some effects. Also, ntpd refuses to adjust the time if the time is too much off.

OTOH, if you dial up only occasionally, it may even make sense to do some time synchronization with ntpdate as part of the post-connect actions.

dp · 2003-10-04 23:16:38

if someone is wondering where to get ntp-server-ip's:

http://www.eecis.udel.edu/~mills/ntp/servers.html

at the bottom you can find stratum 1 and 2 list-links

Bobonov · 2003-10-06 13:19:34

Andy is rigth.
NTPD basicaly adjust gradually the clock. Gradually means that it speed or slow the clock untill it reach the correct time. this ensure that in the log file and in any othe use the time is always consecutive.
It check the time on other ntp server or by time source (eg. GPS device or radio clock, see NTP manual driver section for more detail)
In the configuration you can set the minimum and the maximum interval between each check.
Doing the check it make a statistick and decide when it has to do the next check.
Usually it depends on the uptime, loger it run fewer the check.
It save accuracy info on the local clock in the derive file. It is used to chose the "clock speed" in case of restart.
Just a note: if the local clock has a difference bigger than 5 ours ntp does not start.
Usually just to be sure in the start script (/etc/rc.d/ntpd) I run the following command that set the clock to the current time:

        # Adjust time to make life easy for ntpd
        if [ -f /etc/ntp/step-tickers ]; then
                echo -n "Syncing time for ntpd. "
                /usr/local/bin/ntpdate -s -b -p 8 -u `cat /etc/ntp/step-tickers`
        fi
        # Start daemons.

This just before running the daemon. step-tickers is a file with one or two ntpd server, instead of 'cat ......' you can put directly a ntpd server name

Arch Linux

#1 2003-09-24 22:39:11

How do I set time with ntp?

#2 2003-09-24 22:53:12

Re: How do I set time with ntp?

#3 2003-09-24 23:25:45

Re: How do I set time with ntp?

#4 2003-09-25 00:26:11

Re: How do I set time with ntp?

#5 2003-09-25 07:02:46

Re: How do I set time with ntp?

#6 2003-10-04 23:16:38

Re: How do I set time with ntp?

#7 2003-10-06 13:19:34

Re: How do I set time with ntp?

Board footer