Setup ntp server » Historie » Revision 2
Revision 1 (Jeremias Keihsler, 17.04.2024 10:12) → Revision 2/3 (Jeremias Keihsler, 17.04.2024 10:13)
h1. Install Procedure for ntp-server h2. Requirements To install ntpd you will need the following: * a installed and supported operating system (e.g. CentOS 9.x) * root-access * a fast internet connection h2. Preliminary Note This procedure is based on a documentation supplied by * http://www.cyberciti.biz/faq/rhel-fedora-centos-configure-ntp-client-server/ * http://http://www.gtkdb.de/index_7_576.html * http://linuxwave.blogspot.com/2007/08/setting-up-your-own-ntp-server.html h2. Install Install ntp: <pre><code class="bash"> yum install ntpsec </code></pre> h2. Configure ntp Server <pre><code class="bash"> vim /etc/ntp.conf </code></pre> h3. Use external ntp-Server as reference Basically the ntp.conf is ready configured, so there is nothing to change If there is need to use additional or different ntp-server then add it to the @server@ section <pre><code class="bash"> server 10.13.109.241 iburst </code></pre> h3. Use internal clock as reference This is only necessary if there is no reliable time-source or ntp-server available at all <pre><code class="bash"> server 127.127.1.0 # local clock fudge 127.127.1.0 stratum 4 # set stratum to any value from 0 to 16, the higher the safer, defaults to 10, 4 is working with WinXP and Win7 </code></pre> h3. restrict access from outside <pre><code class="bash"> restrict default nomodify noquery # enable all access for localhost restrict 127.0.0.1 restrict ::1 # enable access from subnet restrict 10.13.109.1/24 nomodify restrict 10.13.108.0/24 </code></pre> h2. Start ntp Server manually start ntp Server: <pre><code class="bash"> systemctl start ntpd </code></pre> automatically start the service at boot time: <pre><code class="bash"> systemctl enable ntpd </code></pre> you can check by <pre><code class="bash"> systemctl is-enabled ntpd </code></pre> h2. configure firewall When you are not running the CentOS Firewall yet, then start it: <pre><code class="shell"> systemctl enable firewalld systemctl start firewalld </code></pre> add chronyd to the firewall if you are going to serve ntp <pre><code class="shell"> firewall-cmd --add-service=ntp --permanent firewall-cmd --reload </code></pre> h2. Usage try to connect via windows machine and enter as a internet-time-source the ip-adress of the new ntp-server. (e.g. 192.168.2.53) try to connect via linux machine and use to sync time: <pre><code class="bash"> ntpdate 192.168.2.53 </code></pre> <pre><code class="bash"> ntpq -p </code></pre>