Linux command
sntp 命令
文本
复制后可按需替换文件名、目录或参数。
常用示例
Query time from an NTP server
sntp [pool.ntp.org]
Step (set) the system clock
sudo sntp -S [pool.ntp.org]
Slew (gradually adjust)
sudo sntp -s [pool.ntp.org]
Query using IPv4 only
sntp -4 [pool.ntp.org]
Query using IPv6 only
sntp -6 [pool.ntp.org]
Use reserved NTP port 123
sudo sntp -r [pool.ntp.org]
说明
sntp is a Simple Network Time Protocol client that queries NTP servers and displays the time offset between the local system clock and the server. With appropriate privileges, it can correct the system clock. Unlike the full ntpd daemon, sntp performs one-time synchronization, making it suitable for cron jobs or scripts where continuous synchronization is unnecessary. It can either step (immediately set) or slew (gradually adjust) the clock. Output shows the time offset and error bounds in seconds, indicating how far the local clock deviates from the server.
参数
- -S, --step
- Step (set) the system clock using settimeofday()
- -s, --slew
- Slew (gradually adjust) the clock using adjtime()
- -4, --ipv4
- Force IPv4 DNS resolution
- -6, --ipv6
- Force IPv6 DNS resolution
- -r, --usereservedport
- Use reserved NTP port 123 for communication
- -M _threshold_
- Slew if offset is less than threshold milliseconds, otherwise step
- -t _seconds_
- Timeout to wait for responses (default: 5)
- -d, --debug-level
- Increase debug verbosity (can be specified multiple times)
- -K _file_, --kod=_file_
- KoD (Kiss-of-Death) history file
- -a _keyid_, --authentication=_keyid_
- Enable authentication with the specified key number
- -b _address_
- Listen to the specified address for broadcast time sync
- -l _file_, --logfile=_file_
- Log status messages to the specified file
- -c, --concurrent
- Send concurrent queries to resolved IPs (for hostnames resolving to multiple addresses on different machines)
FAQ
What is the sntp command used for?
sntp is a Simple Network Time Protocol client that queries NTP servers and displays the time offset between the local system clock and the server. With appropriate privileges, it can correct the system clock. Unlike the full ntpd daemon, sntp performs one-time synchronization, making it suitable for cron jobs or scripts where continuous synchronization is unnecessary. It can either step (immediately set) or slew (gradually adjust) the clock. Output shows the time offset and error bounds in seconds, indicating how far the local clock deviates from the server.
How do I run a basic sntp example?
Run `sntp [pool.ntp.org]` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -S, --step do in sntp?
Step (set) the system clock using settimeofday()