[SunHELP] Help needed to setup NTP

Jim Pennino jimp at specsol.com
Sat Dec 20 01:22:04 CST 2003

On Fri, Nov 21, 2003 at 01:10:18AM -0800, uma reddy wrote:
> Hi! Jim Pennion
> Is there any way ,I can configure the servers without using the reference clock. 
> Regards,
> Uma Reddy

Basically, no.

To simplify a whole lot, one of the basic premises of ntp is that some
where in the system is an accurate and stable source of the real time.

The system clock of a computer is neither accurate nor stable.

The ntp algoriths look at the "goodness" of the time sources; there can
be, and normally are, several. If ntp can't find a suitable source, it
refuses to sync. If a system is not synced, other machines will refuse
to sync to that system.

If there is access to the internet, the solution is simple. You sync
one machine (typically your firewall) to public ntp servers on the 
internet and sync all your internal machines to that system either
directly or indirectly. If you have multiple firewalls, you just chain
them until you get to the lowest level.

If you have no access to the internet at all, your only solution is to
have some local hardware such as a radio or GPS clock to provide accurate

See http://www.ntp.org for a detailed description of how ntp works, lists
of public time servers on the internet, and sources for clock hardware.

BTW, local hardware can be as simple as a Linux box with a sound card
connected to a radio receiver. 

Jim Pennino

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