linux 时间同步ntp和chrony服务搭建配置

admin

查看时间同步源的信息。
. a( W$ g! F1 N) \. D2 V7 p0 R, S# chronyc sourcestats -v
' s3 Z2 R' f" s# E8 ^210 Number of sources = 1
) T( s; s. N2 _9 v                             .- Number of sample points in measurement set.
4 T7 f- g. H/ E- C                            /    .- Number of residual runs with same sign.
1 {5 r: ]! i3 N& D5 b& P+ A                           |    /    .- Length of measurement set (time).
                           |   |    /      .- Est. clock freq error (ppm).
                           |   |   |      /           .- Est. error in freq.
3 F9 q% E3 J+ ]& H                           |   |   |     |           /         .- Est. offset.
3 S) F: K' R8 Z" s& K) `/ T4 ?. Z  y                           |   |   |     |          |          |   On the -.
/ M' s9 ]3 I6 K+ o) J" A+ z) W. [                           |   |   |     |          |          |   samples. \
                           |   |   |     |          |          |             |
+ _$ K1 L( c% @/ R1 |Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
==============================================================================
promote.cache-dns.local     0   0     0     +0.000   2000.000     +0ns  4000ms

admin

[root@361way ~]# chronyc
chrony version 1.29.1
Copyright (C) 1997-2003, 2007, 2009-2013 Richard P. Curnow and others
6 q( ~8 T) Z0 J! v0 l9 f& v+ `chrony comes with ABSOLUTELY NO WARRANTY.  This is free software, and
. k# o2 }, h8 K  G  Lyou are welcome to redistribute it under certain conditions.  See the
GNU General Public License version 2 for details.
6 V* W9 Q; r; S& X# ^8 \. {2 ~5 Pchronyc> activity
- \0 B% n( @  v+ r+ [  t200 OK
3 sources online
0 sources offline
0 sources doing burst (return to online)
6 M. S  y$ a3 P  Q0 sources doing burst (return to offline)
0 sources with unknown address
" s- g( x& ^6 d5 U" Wchronyc> help
. ]- q7 T, I! ]9 X% _% h6 ZCommands:
accheck <address> : Check whether NTP access is allowed to <address>
/ L/ T5 J: d1 P! O5 e  l5 gactivity : Check how many NTP sources are online/offline
3 @6 u% k% S8 e; uadd peer <address> ... : Add a new NTP peer
add server <address> ... : Add a new NTP server
7 E. O9 U/ i8 S( }allow [<subnet-addr>] : Allow NTP access to that subnet as a default
allow all [<subnet-addr>] : Allow NTP access to that subnet and all children
# p0 u3 u; u' Dburst <n-good>/<n-max> [<mask>/<masked-address>] : Start a rapid set of measurements
: b3 ]6 a( z* L: p: y# F1 L: v9 r( Dclients : Report on clients that have accessed the server
cmdaccheck <address> : Check whether command access is allowed to <address>
* ~* H3 ~! D$ V- L3 B4 ~: Kcmdallow [<subnet-addr>] : Allow command access to that subnet as a default
3 c) P' Q' J( M! Lcmdallow all [<subnet-addr>] : Allow command access to that subnet and all children
: g' ^- }0 w) s) @0 i: Lcmddeny [<subnet-addr>] : Deny command access to that subnet as a default
+ T$ X5 Z* Y1 _" G……………………省略

admin

配置NTP server 服务器 #yum install -y ntp
9 b+ e5 @/ l' C1 V; U+ `●        编辑ntp 配置  vim /etc/ntp.conf
driftfile /var/lib/ntp/drift
restrict default nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict ::1
" e* k7 `. |( n4 Qserver 127.127.1.0                              　　
fudge 127.127.1.0 stratum 0                  
7 c5 p3 c. e: m8 Pincludefile /etc/ntp/crypto/pw
# v# F' S# {9 B7 l; Rkeys /etc/ntp/keys
disable monitor
% _6 M/ p5 C1 R6 C# x0 R7 b* ~: O" j& e8 B●        编辑ntp 服务器的配置
# vim  /etc/sysconfig/iptables

  -A INPUT -p udp --dport 123 -j ACCEPT

# systemctl restart iptables
% U$ S$ x, @' ^7 g& u# systemctl restart iptables.service
0 ^* w' A8 j% v●        将系统时间写入硬件
  # hwclock --systohc
●        重新启动NTP服务
    # service ntpd restart
# l2 e/ `8 F6 l. z* ]& c
  V4 E9 @! U$ q8 }

admin

设定NTP主机来源（其中prefer表示优先主机），192.168.7.49是本地的NTP服务器，所以优先指定从该主机同步时间。

server 192.168.7.49 prefer