linux下ntp服务器搭建方法

环境

软件：fedora14，装在virtualbox虚拟机上
硬件：x86

具体步骤

检查是否安装了ntp

运行如下命令：

rpm -qa | grep ntp

如果有如下输出，表示有安装ntp 服务器

ntp-4******** 

如果有如下输出，表示有安装ntp客户端

ntpdate-****** 

如果没有安装，执行 yum -y install ntp

修改ntp的配置文件

用文件ntp.conf替换掉/etc/ntp.conf文件，ntp.conf内容如下

    # For more information about this file, see the man pages
    # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).

    driftfile /var/lib/ntp/drift

    # Permit time synchronization with our time source, but do not
    # permit the source to query or modify the service on this system.

    # rongp comment
    #restrict default kod nomodify notrap nopeer noquery
    #restrict -6 default kod nomodify notrap nopeer noquery
    restrict 192.168.1.94
    restrict 192.168.1.0 mask 255.255.255.0 nomodify
    # Permit all access over the loopback interface. This could
    # be tightened as well, but to do so would effect some of
    # the administrative functions.
    # rongp comment
    # 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
    server ntp.amnic.net prefer
    server time.windows.com prefer
    server time-nw.nist.gov prefer
    server time.nist.gov prefer

    restrict ntp.amnic.net
    restrict time.windows.com
    restrict time-nw.nist.gov
    restrict time.nist.gov prefer

    # Use public servers from the pool.ntp.org project.
    # Please consider joining the pool (http://www.pool.ntp.org/join.html).
    # rongp comment
    # server 0.fedora.pool.ntp.org iburst
    # server 1.fedora.pool.ntp.org iburst
    # server 2.fedora.pool.ntp.org iburst
    # server 3.fedora.pool.ntp.org iburst

    #broadcast 192.168.1.255 autokey # broadcast server
    #broadcastclient # broadcast client
    #broadcast 224.0.1.1 autokey # multicast server
    #multicastclient 224.0.1.1 # multicast client
    #manycastserver 239.255.254.254 # manycast server
    #manycastclient 239.255.254.254 autokey # 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

    # Enable public key cryptography.
    #crypto

    includefile /etc/ntp/crypto/pw

    # 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

    # Enable writing of statistics records.
    #statistics clockstats cryptostats loopstats peerstats

重启ntp服务器

执行命令： service ntpd restart

检查是否正常开启ntp服务器

执行命令： ps -ef | grep ntpd | grep -v grep

如果有输出表示已开启，然后用客户端进一步测试能否正常同步到该ntp服务器，用另外一台电脑（需要安装ntpdate)，执行ntpdate ntp服务器地址 eg: ntpdate 192.168.1.94

如果有如下类似输出：

28 May 17:33:39 ntpdate[29134]: step time server 192.168.1.94 offset 3.174187 sec

表示同步成功。

注意：刚开启的ntp服务器需要过几分钟后客户端才能够去同步，因为ntp服务器本身要和远程ntp服务器同步需要时间，因此可能会遇到如下出错信息：

28 May 17:32:00 ntpdate[29104]: no server suitable for synchronization found

这种情况，过几分钟后再试试，这个情况还可能是其他原因导致，这里不再描述。

附录

配置文件说明：

restrict开头的行，表示设置客户端连接到本ntp服务器的权限
server开头的行，表示设置本ntp服务器连接到远程ntp服务器的地址
server 127.127.1.0 # local clock
fudge 127.127.1.0 stratum 10

上面两行的意思是如果server指定的服务器连接失败，采用本地的时间来同步时间

完！
2012年6月