呂阿谷的部落格

安裝：

yum install ntp -y

設定：

主要設定檔 /etc/ntpd.conf

vim /etc/ntpd.conf

restrict tock.stdtime.gov.tw
restrict tick.stdtime.gov.tw
restrict time.stdtime.gov.tw

#restrict 211.22.103.157
#restrict 118.163.81.62
#restrict 118.163.81.61

restrict 10.0.0.0 mask 255.0.0.0 nomodify

可用上面也可用下面，用IP address萬一NTP server搬家就比較麻煩了，下面ip對應上方的server，

這是限制可以修改ntp server的主機，我的區網IP網段是10.，nomodify限制只能讀不能改。

#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

server tock.stdtime.gov.tw prefer
server tick.stdtime.gov.tw
server time.stdtime.gov.tw

#server 211.22.103.157 prefer
#server 118.163.81.62
#server 118.163.81.61

這是設定上層NTP server主機名稱或是ip位址，紅色部份是centos安裝後預設的server，

註記掉後改用台灣的server，下方主機名稱與ip同上。

設好儲存檔案之後離開。

接下來修改 /etc/sysconfig/ntpd，設定 BIOS 的時間也同步調整

 vim /etc/sysconfig/ntpd

# Drop root to id 'ntp:ntp' by default.
OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid -g"
SYNC_HWCLOCK=yes

啟動ntpd

service ntpd start

檢查是否有正確執行(需要等一段時間讓ntp server與上層同步完成)：

ntpstat

synchronised to NTP server (211.22.103.157) at stratum 3
   time correct to within 104 ms
   polling server every 64 s

出現以上字樣即表示已經與上層server完成同步。

也可以使用 ntpq -p 指令檢查time server設定是否正確：

ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*211-22-103-157. 192.168.0.2      2 u   16   64  377   14.384  -33.557  10.717
+118-163-81-62.H 192.168.0.2      2 u   18   64  377   14.019  -49.612  10.504
+118-163-81-61.H 192.168.0.3      2 u   20   64  377   14.273  -30.676  12.552

到此完成時間伺服的安裝與設定。

完整 nptd.conf 如下，可以直接copy去用：

# 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.
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

restrict tock.stdtime.gov.tw
restrict tick.stdtime.gov.tw
restrict time.stdtime.gov.tw

#restrict 211.22.103.157
#restrict 118.163.81.62
#restrict 118.163.81.61


restrict 10.0.0.0 mask 255.0.0.0 nomodify

# 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 iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst

server tock.stdtime.gov.tw prefer
server tick.stdtime.gov.tw
server time.stdtime.gov.tw

#server 211.22.103.157 prefer
#server 118.163.81.62
#server 118.163.81.61


#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