CentOS 设置内网时间同步

古城微笑少年丶 2022-12-30 08:21 245阅读 0赞

因我是centos6  centos7同理，仅仅启动关闭服务命令不一样而已。

规划：

172.29.251.159 时间同步服务端，局域网内以此服务器为时间源

其他同网段机器作为客户端，向172.29.251.159发起同步请求

镜像源头：[https://www.cnblogs.com/haizhisha/p/12698140.html][https_www.cnblogs.com_haizhisha_p_12698140.html]

**在所有机器上安装ntp**

yum -y install ntp

**所有机器上**设置开机启动

chkconfig ntpd on

**所有机器上**开启服务

service ntpd start

**172.29.251.159 上配置**

删除/etc/ntp.conf所有内容

echo > /etc/ntp.conf

增加文本

vi /etc/ntp.conf

修改成以下内容

# 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).
    #记录system clock的误差值开机时不会丢失
    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.
    #默认拒绝所有来源的任何访问
    restrict default 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.
    #允许本机地址一切操作
    restrict 127.0.0.1
    restrict ::1
    
    # Hosts on local network are less restricted.
    #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap#restrict 对ntp做权限控制 ignore：忽略所有类型的NTP连接请求 nomodify：限制客户端不能使用命令ntpc和ntpq来修改服务器端的时间#noquery：不提供NTP网络校时服务 notrap：不接受远程登录请求 notrust：不接受没有经过认证的客户端的请求
    #允许局域网172.29.251网段内所有client连接到这台服务器同步时间.但是拒绝让他们修改服务器上的时间和远程登录
    restrict 172.29.251 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 iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst
    
    #指定ntp服务器的地址
    #将当前主机作为时间服务器
    server 127.127.1.0
    #时间服务器层级0-15 0表示顶级 10通常用于给局域网主机提供时间服务
    fudge 127.127.1.0 stratum 10
    
    #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
    
    # 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
    
    # Disable the monitoring facility to prevent amplification attacks using ntpdc
    # monlist command when default restrict does not include the noquery flag. See
    # CVE-2013-5211 for more details.
    # Note: Monitoring will not be disabled with the limited restriction flag.
    disable monitor

重启server端

service ntpd restart

查看状态

[root@master ~]# ntpstat
    synchronised to local net (127.127.1.0) at stratum 11
       time correct to within 7948 ms
       polling server every 64 s
    [root@master ~]#

**设置 client端**

删除/etc/ntp.conf所有内容

echo > /etc/ntp.conf
    vi /etc/ntp.conf

# 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 iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst#client端仅仅加入server端IP
    server 时间服务ip
    
    #比如：我的
    #server  172.29.251.159

重启client端

service ntpd restart

检查网络中的NTP服务器

[root@node1 ~]# ntpq -p
         remote           refid      st t when poll reach   delay   offset  jitter
    ==============================================================================
    *master          LOCAL(0)        11 u   43   64   37    0.223  -134.33  92.058
    [root@node1 ~]#

以crontab任务计划同步时间（需安装ntpdate，每天24点更新同步时间）：

# crontab -e
    0 0 * * * /usr/sbin/sntp -P no -r 172.29.251.159;hwclock -w

\*表示目前使用的NTP Server，这里选择的本机；

st：即stratum阶层，值越小表示ntp serve的精准度越高；

when：单位秒，几秒前曾做过时间同步更新的操作；

poll表示，每隔多少毫秒与ntp server同步一次；

reach：已经向上层NTP服务器要求更新的次数；

delay：网络传输过程钟延迟的时间；

offset：时间补偿的结果；

jitter：Linux系统时间与BIOS硬件时间的差异时间

遇到的问题：

# \[Errno 14\] PYCURL ERROR 22 阿里yum源安装，centos 6已停止维护 #

[https://blog.csdn.net/qq\_37746897/article/details/110759717?utm\_medium=distribute.pc\_relevant.none-task-blog-baidujs\_title-3&spm=1001.2101.3001.4242][https_blog.csdn.net_qq_37746897_article_details_110759717_utm_medium_distribute.pc_relevant.none-task-blog-baidujs_title-3_spm_1001.2101.3001.4242]

参考文献；

[https://www.cnblogs.com/hdfserror01/p/13769883.html][https_www.cnblogs.com_hdfserror01_p_13769883.html]

[https://www.linuxprobe.com/centos7-ntp-time.html][https_www.linuxprobe.com_centos7-ntp-time.html]

[https://www.cnblogs.com/haizhisha/p/12698140.html][https_www.cnblogs.com_haizhisha_p_12698140.html]

[https_www.cnblogs.com_haizhisha_p_12698140.html]: https://www.cnblogs.com/haizhisha/p/12698140.html
[https_blog.csdn.net_qq_37746897_article_details_110759717_utm_medium_distribute.pc_relevant.none-task-blog-baidujs_title-3_spm_1001.2101.3001.4242]: https://blog.csdn.net/qq_37746897/article/details/110759717?utm_medium=distribute.pc_relevant.none-task-blog-baidujs_title-3&spm=1001.2101.3001.4242
[https_www.cnblogs.com_hdfserror01_p_13769883.html]: https://www.cnblogs.com/hdfserror01/p/13769883.html
[https_www.linuxprobe.com_centos7-ntp-time.html]: https://www.linuxprobe.com/centos7-ntp-time.html