Re: NTP.conf pool vs server
- Date: Wed, 07 Jun 2017 07:41:14 -0700
- From: Kushal Kumaran <kushal@xxxxxxxxxxxxx>
- Subject: Re: NTP.conf pool vs server
ray <ray@xxxxxxxxx> writes:
> I would like to know the correct syntax for entering a server entry for stretch.
> All the documentation I find says to list the ntp servers in the file as:
> server 0.XX.pool.ntp.org
> server 1.XX.pool.ntp.org
> An example source from 2017 is https://wiki.debian.org/DateTime
> When I open /etc/ntp.conf on my new stretch installation, I find this format:
> pool 0.debian.pool.ntp.org iburst
> pool 1.debian.pool.ntp.org iburst
> The latest Debian doc says to start the line with 'server'.
> The latest Debian implementation starts the line with 'pool'.
> Are these interchangeable?
No. A server entry will setup a single NTP server. A pool entry can
setup several. You can experiment by configuring a single pool and then
looking at how may peers are reported by ntpq -c peers. I don't know
the details of how it works, but I'm guessing "server" looks up IPs for
hostname and uses only one of those (like typical uses of hostname),
while "pool" looks up IPs and uses all of them.
> Additionally, there is a parameter 'iburst' which I did not find in the Debian docs but found at http://doc.ntp.org/4.1.1/confopt.htm