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在linux下用ntpdate更新时间
  • 2014-07-21发布
  • 2014-07-21修改

ntpd是linux自动同步时间服务,它提供ntpdate命令让用户可以手动同步时间服务器的时间

一、安装

[root@myserver]#  yum install ntp -y

二、用cat命令查看ntp的配置:

[root@myserver]#  cat /etc/ntp.conf

========================

# Permit time synchronization with our time source, but do not

# permit the source to query or modify the service on this system.

restrict default kod nomodify notrap nopeer noquery

restrict -6 default kod nomodify notrap nopeer noquery

# Permit all access over the loopback interface.  This could

# be tightened as well, but to do so would effect some of

# the administrative functions.

restrict 127.0.0.1 

restrict -6 ::1

# Hosts on local network are less restricted.

#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

# Use public servers from the pool.ntp.org project.

# Please consider joining the pool (http://www.pool.ntp.org/join.html).

server 0.centos.pool.ntp.org

server 1.centos.pool.ntp.org

server 2.centos.pool.ntp.org

#broadcast 192.168.1.255 key 42         # broadcast server

#broadcastclient                        # broadcast client

#broadcast 224.0.1.1 key 42             # multicast server

#multicastclient 224.0.1.1              # multicast client

#manycastserver 239.255.254.254         # manycast server

#manycastclient 239.255.254.254 key 42  # manycast client

# Undisciplined Local Clock. This is a fake driver intended for backup

# and when no outside source of synchronized time is available. 

server  127.127.1.0     # local clock

fudge   127.127.1.0 stratum 10

# Drift file.  Put this in a directory which the daemon can write to.

# No symbolic links allowed, either, since the daemon updates the file

# by creating a temporary in the same directory and then rename()'ing

# it to the file.

driftfile /var/lib/ntp/drift

# Key file containing the keys and key identifiers used when operating

# with symmetric key cryptography. 

keys /etc/ntp/keys

# Specify the key identifiers which are trusted.

#trustedkey 4 8 42

# Specify the key identifier to use with the ntpdc utility.

#requestkey 8

# Specify the key identifier to use with the ntpq utility.

#controlkey 8

========================

红色部分是默认的ntp服务器地址,找出来以备ntpdate 使用

三、用ntpdate同步时间

[root@myserver]#  ntpdate 0.centos.pool.ntp.org

返回类似以下结果表示同步成功:

20 Apr 13:42:37 ntpdate[8004]: step time server 114.80.81.13 offset -167.375072 sec