Use pool.ntp.org in ntpd configuration and request iburst for faster initial synchronization.
Which ntp.conf line is appropriate?
The pool directive expands a DNS name into multiple time sources, while iburst sends initial probes at short intervals.
Detailed explanation
server=pool.ntp.org iburstIncorrect. ntp.conf does not use this equals form for server lines.
nameserver pool.ntp.org iburstIncorrect. nameserver is a resolver configuration directive.
chronyc pool pool.ntp.org iburstIncorrect. This is a chronyc command rather than an ntp.conf line.
pool pool.ntp.org iburstCorrect. It defines the pool and iburst option.
Try it yourself
An example you can run in a temporary verification environment.
printf '%s
' 'pool pool.ntp.org iburst' | awk '{print $1, $2, $3}'Expected result
pool pool.ntp.org iburstKey points
- pool directive
- pool.ntp.org
- iburst speeds initial sync
Notes
- Environment: POSIX awk / 模擬設定のみ
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
System clock
The kernel-maintained time used by applications and timestamps.
RTC
The battery-backed hardware clock used to seed time during boot.
NTP synchronization
A process that compares a clock with remote time sources and corrects drift.