Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Network Services Overview NTP ====== **General Information** This page covers the Network Services objectives, specifically for NTP. **Network Services Objectives** * Install the packages needed to provide the service * Configure SELinux to support the service * Use SELinux port labeling to allow services to use non-standard ports * Configure the service to start when the system is booted * Configure the service for basic operation * Configure host-based and user-based security for the service ---- ====== Lab Setup ====== The following virtual machines will be used: * ipa.example.com (192.168.1.152) -> Central Time Server * server1.example.com (192.168.1.150) -> NTP Server1 syncs with central (also peers with server2) * server2.example.com (192.168.1.151) -> NTP Server2 syncs with central (also peers with server1) ---- ====== Install the packages needed to provide the service ====== Install the service (default in RHEL 7) <code bash> yum install chrony </code> ---- ====== Configure SELinux to support the service ====== * Service agnostic -> [[linux_wiki:set_enforcing_and_permissive_modes_for_selinux|Ensure SELinux is running and enabled (RHCSA objective)]]. ---- ====== Use SELinux port labeling to allow services to use non-standard ports ====== Configuring the <service-name> with a non standard port and allowing port access with selinux. **NOTE**: "man semanage-port" has examples for allowing non-standard ports! ---- ====== Configure the service to start when the system is booted ====== Check Current Service Status <code bash> systemctl status chronyd </code> * Also displays if the service is enabled or disabled \\ Enabling a service to start on boot <code bash> systemctl enable chronyd </code> ---- ====== Configure the service for basic operation ====== Enable and Start the service <code bash> systemctl enable chronyd systemctl start chronyd </code> ---- ====== Configure host-based and user-based security for the service ====== ===== Firewall ===== Allow access through the firewall if you want other servers to sync to this system <code bash> firewall-cmd --permanent --add-service=ntp firewall-cmd --reload </code> ===== Host Based ===== ===== User Based ===== ---- linux_wiki/network_services_overview_ntp.txt Last modified: 2019/05/25 23:50(external edit)