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talk:howtos:network_services:ntp [2012/09/25 03:12 (UTC)] – moved the page from the general howtos namespace mfillpottalk:howtos:network_services:ntp [2014/08/28 20:26 (UTC)] – streamthreader
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 Thanks, Niki, I learned something today!  ;-) (isn't that what this wiki is all about?) Thanks, Niki, I learned something today!  ;-) (isn't that what this wiki is all about?)
 +
 +----
 +\\
 +Deordiev Oleg notes about article:\\
 +For understand NTP engine and program, i read special book, and write article on [[http://blog.ifconfig.com.ua/?p=117|ukrainian]] language.\\
 +Some recommendation (used around Internet) about ntpd - is wrong (for new versions of ntpd).\\
 +For example:\\
 +1)\\
 +Directive "server" used for one domain name or IP address.\\
 +Directive "pool" used for CNAME with list of more than one IP address (for example 0.ua.pool.ntp.org is a pool of ip addresses) (NTP if "pool" use export list of IPs from CNAME).\\
 +As a result, in ntp world have 2x types of server - this is s "server" and "pool". And use server directive for pool - is wrong.\\
 +
 +2)\\
 +Method - Undisciplined Local Clock driver is old:\\
 + server 127.127.1.0\\
 + fudge 127.127.1.0 stratum 10\\
 +For short it use only for local net without access to Internet.
 +And very important if you have Internet in mode local clock, you need set PREFER argument for external source of time, because only this argument can override FUDGE modifier. If not use Prefer arg. NTP automatically set local time as only one right source of time, even if exist connection with external source (NTP even not check connection with it, and permanent set itself as valid source).\\
 +This driver is old, and not provide redundant.\\
 +
 +For new version NTP (newer then 4.2.2 (2006-06-08)) need use Orphan-Mode Driver.\\
 +Delete directives:\\
 + server 127.127.1.0\\
 + fudge 127.127.1.0 stratum 10\\
 +And use:\\
 + tos orphan 5\\
 +For set itself Stratum 5 if external sources is not reachable, after 60 sec (can ovveride this by set: tos orphanwait 60).
 +This option set in some servers in local net (for examples 2 server with NTP) and enumerate one itself other "cross", and if one of it get valid time, other server sync with it. This provide redundancy.
 +
 +Config for example:\\
 +
 +
 +**Server-1 (192.168.68.1)**\\
 +
 +server 192.168.68.2 burst iburst\\
 +server 62.149.0.30\\
 +pool 0.ua.pool.ntp.org\\
 +pool 1.ua.pool.ntp.org\\
 +pool 2.ua.pool.ntp.org\\
 +pool 3.ua.pool.ntp.org\\
 +
 +tos orphan 10\\
 +tinker panic 0\\
 +
 +keys /etc/ntp/keys\\
 +driftfile /etc/ntpd.drift\\
 +logfile /var/log/ntp.log\\
 +pidfile /var/run/ntpd.pid\\
 +
 +restrict default ignore\\
 +restrict 127.0.0.1\\
 +restrict 192.168.0.0 mask 255.255.0.0 nomodify notrap\\
 +
 +restrict 192.168.68.2 notrap noquery nomodify\\
 +restrict 62.149.0.30 notrap noquery nomodify\\
 +restrict 0.ua.pool.ntp.org noquery notrap\\
 +restrict 1.ua.pool.ntp.org noquery notrap\\
 +restrict 2.ua.pool.ntp.org noquery notrap\\
 +restrict 3.ua.pool.ntp.org noquery notrap\\
 +
 +
 +**Server-2 (192.168.68.2)**
 +
 +server 192.168.68.1 burst iburst\\
 +server 62.149.0.30\\
 +pool 0.ua.pool.ntp.org\\
 +pool 1.ua.pool.ntp.org\\
 +pool 2.ua.pool.ntp.org\\
 +pool 3.ua.pool.ntp.org\\
 +
 +tos orphan 10\\
 +tinker panic 0\\
 +
 +keys /etc/ntp/keys\\
 +driftfile /etc/ntpd.drift\\
 +logfile /var/log/ntp.log\\
 +pidfile /var/run/ntpd.pid\\
 +
 +restrict default ignore\\
 +restrict 127.0.0.1\\
 +restrict 192.168.0.0 mask 255.255.0.0 nomodify notrap\\
 +
 +restrict 192.168.68.1 notrap noquery nomodify\\
 +restrict 62.149.0.30 notrap noquery nomodify\\
 +restrict 0.ua.pool.ntp.org noquery notrap\\
 +restrict 1.ua.pool.ntp.org noquery notrap\\
 +restrict 2.ua.pool.ntp.org noquery notrap\\
 +restrict 3.ua.pool.ntp.org noquery notrap\\
 +
 +
 +**Client (192.168.68.100)**
 +
 +server 192.168.68.1 iburst burst\\
 +server 192.168.68.2 iburst burst\\
 +
 +tinker panic 0\\
 +
 +driftfile /etc/ntpd.drift\\
 +logfile /var/log/ntp.log\\
 +pidfile /var/run/ntpd.pid\\
 +
 +restrict default ignore\\
 +
 +restrict 192.168.68.1 noquery notrap\\
 +restrict 192.168.68.2 noquery notrap\\
 +restrict 127.0.0.1\\
 +
 +
 +
 +Server NTP with Orphan mode can by even One. But for all right - need some servers.
 +
 +For very detail info read book [[http://www.amazon.com/Computer-Network-Time-Synchronization-Protocol/dp/1439814635|The Network Time Protocol on Earth and in Space]] because i not provide very clear and right English for understand. But if you can questions, can write my.
 +
 +
 +

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