change polling time for NTP

[Ratzie]

How do you shorten the polling time for NTP?

[G. Vrijhoeven · Accepted solution]

Hi,


Check:
http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90774/B2355-90774_top.html&con=/hpux/onlinedocs/B2355-90774/00/00/24-con.html&toc=/hpux/onlinedocs/B2355-90774/00/00/24-toc.html&searchterms=polling&queryid=20040109-114300

it states:
The poll (poll period) column indicates the polling interval to the remote host, as determined by xntpd. You can define the minimum polling interval with the minpoll option in the peer, server, or broadcast definitions in the /etc/ntp.conf file. Some popular values for network connections include 512 and 1024 seconds (approximately 8 mins. and 17 mins.). Systems with external clocks, like GPS, must poll every 64 seconds or less.


HTH,

Gideon

[Bill Hassell]

The minimum poll time is 64 seconds and xntpd will stay at this setting until accuracy is better than 128ms. Then the poll time is increased as long as accuracy is still the same. The NTP protocol is quite complex to ensure the local clock never gains or loses a clock tick and maintains the 128ms accrarcy. There is no need to change the polling time.

If your system is no keeping accurate time, use ntpq -p to see if any of your NTP servers are working. You should have at least 3 or 4 servers for reliability. Look also at syslog (grep xntpd /var/adm/syslog/syslog.log). Do NOT use ntpdate in a cron job for time sync.