ntp服务器设置与client同步（rhel5.3）

1.ntp服务端配置需要2个rpm数据包：ntp，tzdata（Time zone data）
2.安装可以通过rpm安装或者yum来安装。
3.配置ntp服务器
vi /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

# 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

# Hosts on local network are less restricted.
#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
restrict 192.168.16.0 mask 255.255.255.0 nomodify--客户端不能使用ntpc与ntpq来修改服务器，但是可以通过ntp服务器来校时。
restrict 10.0.5.0 mask 255.255.255.0 nomodify

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool ().
server 0.asia.pool.ntp.org prefer---有线使用这个服务器来校时，
server 1.asia.pool.ntp.org
server 2.asia.pool.ntp.org
server 3.asia.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
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
restrict 58.73.137.250 mask 255.255.255.255 nomodify notrap noquery
restrict 81.91.129.87 mask 255.255.255.255 nomodify notrap noquery
server 119.110.97.148
restrict None mask 255.255.255.255 nomodify notrap noquery
restrict 85.154.254.78 mask 255.255.255.255 nomodify notrap noquery
server 61.153.197.226
restrict 61.153.197.226 mask 255.255.255.255 nomodify notrap noquery

4.时间校准后，只是在系统中有效，还要写入bios才行，具体操作如下：
vi /etc/sysconfig/ntpd
# Drop root to id 'ntp:ntp' by default.
OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid"

# Set to 'yes' to sync hw clock after successful ntpdate
SYNC_HWCLOCK=no-----把此处no改为yes

5，启动ntp服务：
service ntpd start

客户端设置：
vi /etc/ntp/ntpservers
#This file contains a list of ntp servers to show in the system-config-date userr
 interface.
#It is not recommended that you modify this file by hand.

ntp.xxx.xxx.cn----添加一个ntp服务器的地址

然后启动ntp服务！