"CentOS ntp 설치"의 두 판 사이의 차이

2020년 11월 2일 (월) 00:55 기준 최신판

✔️ CentOS 6에서 테스트하였습니다.

CentOS ntp 설치

1 확인[ | ]

[root@zetawiki ~]# rpm -qa ntp
[root@zetawiki ~]# yum list ntp
... (생략)
Available Packages
ntp.x86_64                    4.2.6p5-5.el6.centos.4                     updates

→ updates 저장소를 통해 설치가능

2 설치[ | ]

[root@zetawiki ~]# yum install ntp
... (생략)
================================================================================
 Package       Arch         Version                         Repository     Size
================================================================================
Installing:
 ntp           x86_64       4.2.6p5-5.el6.centos.4          updates       595 k
Installing for dependencies:
 ntpdate       x86_64       4.2.6p5-5.el6.centos.4          updates        77 k

Transaction Summary
================================================================================
Install       2 Package(s)

Total download size: 672 k
Installed size: 1.7 M
Is this ok [y/N]: y

... (생략)
Installed:
  ntp.x86_64 0:4.2.6p5-5.el6.centos.4                                                                

Dependency Updated:
  ntpdate.x86_64 0:4.2.6p5-5.el6.centos.4                                                            

Complete!

3 확인 2[ | ]

[root@zetawiki ~]# rpm -qa ntp
ntp-4.2.6p5-5.el6.centos.4.x86_64

4 설치 위치 확인[ | ]

[root@zetawiki ~]# whereis ntp
ntp: /etc/ntp /etc/ntp.conf
[root@zetawiki ~]# which ntpq
/usr/sbin/ntpq
[root@zetawiki ~]# which ntpdate
/usr/sbin/ntpdate
[root@zetawiki ~]# which ntpd
/usr/sbin/ntpd
[root@zetawiki ~]# service ntpd status
ntpd is stopped

설정파일 ntp.conf는 /etc에 있다.
ntpq, ntpdate, ntpd는 /usr/sbin에 있다.
ntpd는 중지된 상태이다.

5 동기화 서버 설정[ | ]

공용 ntp 서버 목록 문서를 참고하십시오.

/etc/ntp.conf 문서를 참고하십시오.

chkconfig ntpd on
echo driftfile /var/lib/ntp/drift > /etc/ntp.conf
echo restrict default kod nomodify notrap nopeer noquery >> /etc/ntp.conf
echo restrict -6 default kod nomodify notrap nopeer noquery >> /etc/ntp.conf
echo restrict 127.0.0.1 >> /etc/ntp.conf
echo restrict -6 ::1 >> /etc/ntp.conf
echo server 1.kr.pool.ntp.org >> /etc/ntp.conf
echo server 1.asia.pool.ntp.org >> /etc/ntp.conf
echo server 2.asia.pool.ntp.org >> /etc/ntp.conf
echo includefile /etc/ntp/crypto/pw >> /etc/ntp.conf
echo keys /etc/ntp/keys >> /etc/ntp.conf
service ntpd restart
ntpq -p

6 즉시 동기화[ | ]

명령어

ntpdate 서버주소

실행 예시

[root@zetawiki ~]# ntpdate time.windows.com

7 차이 보기[ | ]

명령어

ntpdate -d 서버주소

실행 예시

[root@zetawiki ~]# ntpdate -d time.windows.com
 2 Oct 02:08:06 ntpdate[3166]: ntpdate 4.2.4p8@1.1612-o Tue Nov 29 00:09:13 UTC 2011 (1)
Looking for host time.windows.com and service ntp
host found : wwwco1test13.microsoft.com
transmit(65.55.21.21)
receive(65.55.21.21)
transmit(65.55.21.21)
receive(65.55.21.21)
transmit(65.55.21.21)
receive(65.55.21.21)
transmit(65.55.21.21)
receive(65.55.21.21)
transmit(65.55.21.21)
server 65.55.21.21, port 123
stratum 2, precision -6, leap 00, trust 000
refid [65.55.21.21], delay 0.19615, dispersion 0.00293
transmitted 4, in filter 4
reference time:    d4144c6a.71b59070  Tue, Oct  2 2012  2:07:54.444
originate timestamp: d4144c77.e83cbb72  Tue, Oct  2 2012  2:08:07.907
transmit timestamp:  d4144c77.cca0c88c  Tue, Oct  2 2012  2:08:07.799
filter delay:  0.22122  0.19688  0.19693  0.19615 
         0.00000  0.00000  0.00000  0.00000 
filter offset: 0.010714 0.029665 0.029863 0.030388
         0.000000 0.000000 0.000000 0.000000
delay 0.19615, dispersion 0.00293
offset 0.030388

 2 Oct 02:08:07 ntpdate[3166]: adjust time server 65.55.21.21 offset 0.030388 sec

→ 마지막 offset 값이 양수이면 로컬서버가 늦는 것, 음수이면 로컬서버가 빠른 것.

→ 로컬 서버가 약 0.03초 늦다.

8 같이 보기[ | ]

@@ 3번째 줄: / 3번째 줄: @@
 ==확인==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# rpm -qa ntp
 [root@zetawiki ~]# yum list ntp
@@ 9번째 줄: / 9번째 줄: @@
 Available Packages
 ntp.x86_64                    4.2.6p5-5.el6.centos.4                     updates
-</source>
+</syntaxhighlight>
 :→ updates 저장소를 통해 설치가능
 ==설치==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# yum install ntp
 ... (생략)
@@ 31번째 줄: / 31번째 줄: @@
 Installed size: 1.7 M
 Is this ok [y/N]: y
-</source>
+</syntaxhighlight>
-<source lang='console'>
+<syntaxhighlight lang='console'>
 ... (생략)
 Installed:
@@ 41번째 줄: / 41번째 줄: @@
 Complete!
-</source>
+</syntaxhighlight>
 ==확인 2==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# rpm -qa ntp
 ntp-4.2.6p5-5.el6.centos.4.x86_64
-</source>
+</syntaxhighlight>
 ==설치 위치 확인==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# whereis ntp
 ntp: /etc/ntp /etc/ntp.conf
@@ 61번째 줄: / 61번째 줄: @@
 [root@zetawiki ~]# service ntpd status
 ntpd is stopped
-</source>
+</syntaxhighlight>
 *설정파일 ntp.conf는 /etc에 있다.
 *ntpq, ntpdate, ntpd는 /usr/sbin에 있다.
@@ 69번째 줄: / 69번째 줄: @@
 {{참고|공용 ntp 서버 목록}}
 {{참고|/etc/ntp.conf}}
-<source lang='bash'>
+<syntaxhighlight lang='bash'>
 chkconfig ntpd on
 echo driftfile /var/lib/ntp/drift > /etc/ntp.conf
@@ 83번째 줄: / 83번째 줄: @@
 service ntpd restart
 ntpq -p
-</source>
+</syntaxhighlight>
 ==즉시 동기화==
 ;명령어
-<source lang='bash'>
+<syntaxhighlight lang='bash'>
 ntpdate 서버주소
-</source>
+</syntaxhighlight>
 ;실행 예시
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# ntpdate time.windows.com
-</source>
+</syntaxhighlight>
 ==차이 보기==
 ;명령어
-<source lang='bash'>
+<syntaxhighlight lang='bash'>
 ntpdate -d 서버주소
-</source>
+</syntaxhighlight>
 ;실행 예시
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# ntpdate -d time.windows.com
 Oct 02:08:06 ntpdate[3166]: ntpdate 4.2.4p8@1.1612-o Tue Nov 29 00:09:13 UTC 2011 (1)
@@ 132번째 줄: / 132번째 줄: @@
 Oct 02:08:07 ntpdate[3166]: adjust time server 65.55.21.21 offset 0.030388 sec
-</source>
+</syntaxhighlight>
 :→ 마지막 offset 값이 양수이면 로컬서버가 늦는 것, 음수이면 로컬서버가 빠른 것.
 :→ 로컬 서버가 약 0.03초 늦다.