"CentOS ntp 설치"의 두 판 사이의 차이

2020년 11월 2일 (월) 00:40 판

✔️ CentOS 6에서 테스트하였습니다.

CentOS ntp 설치

1 확인

<syntaxhighlight lang='console'> [root@zetawiki ~]# rpm -qa ntp [root@zetawiki ~]# yum list ntp ... (생략) Available Packages ntp.x86_64 4.2.6p5-5.el6.centos.4 updates </source>

→ updates 저장소를 통해 설치가능

2 설치

<syntaxhighlight lang='console'> [root@zetawiki ~]# yum install ntp ... (생략)

2.1 ====================================================================

Package       Arch         Version                         Repository     Size

2.2 ====================================================================

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

2.3 ====================================================================

Install 2 Package(s)

Total download size: 672 k Installed size: 1.7 M Is this ok [y/N]: y </source> <syntaxhighlight lang='console'> ... (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! </source>

3 확인 2

<syntaxhighlight lang='console'> [root@zetawiki ~]# rpm -qa ntp ntp-4.2.6p5-5.el6.centos.4.x86_64 </source>

4 설치 위치 확인

<syntaxhighlight lang='console'> [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 </source>

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.

<syntaxhighlight lang='bash'> 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 </source>

6 즉시 동기화

명령어

<syntaxhighlight lang='bash'> ntpdate 서버주소 </source>

실행 예시

<syntaxhighlight lang='console'> [root@zetawiki ~]# ntpdate time.windows.com </source>

7 차이 보기

명령어

<syntaxhighlight lang='bash'> ntpdate -d 서버주소 </source>

실행 예시

<syntaxhighlight lang='console'> [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

</source>

→ 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
@@ 13번째 줄: / 13번째 줄: @@
 ==설치==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# yum install ntp
 ... (생략)
@@ 32번째 줄: / 32번째 줄: @@
 Is this ok [y/N]: y
 </source>
-<source lang='console'>
+<syntaxhighlight lang='console'>
 ... (생략)
 Installed:
@@ 44번째 줄: / 44번째 줄: @@
 ==확인 2==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# rpm -qa ntp
 ntp-4.2.6p5-5.el6.centos.4.x86_64
@@ 50번째 줄: / 50번째 줄: @@
 ==설치 위치 확인==
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# whereis ntp
 ntp: /etc/ntp /etc/ntp.conf
@@ 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
@@ 87번째 줄: / 87번째 줄: @@
 ==즉시 동기화==
 ;명령어
-<source lang='bash'>
+<syntaxhighlight lang='bash'>
 ntpdate 서버주소
 </source>
 ;실행 예시
-<source lang='console'>
+<syntaxhighlight lang='console'>
 [root@zetawiki ~]# ntpdate time.windows.com
 </source>
@@ 98번째 줄: / 98번째 줄: @@
 ==차이 보기==
 ;명령어
-<source lang='bash'>
+<syntaxhighlight lang='bash'>
 ntpdate -d 서버주소
 </source>
 ;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)