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How to install chrony in Linux

To install Chrony on CentOS, you can use the package manager yum. Here are the steps to install Chrony:

  1. Open a terminal on your CentOS system.
  2. Make sure your system is updated by running the following command:bashCopy codesudo yum update
  3. Install Chrony using the following command:bashCopy codesudo yum install chrony
  4. Once the installation is complete, you can start and enable the Chrony service to ensure it starts automatically on boot:bashCopy codesudo systemctl start chronyd sudo systemctl enable chronyd
  5. Check the status of the Chrony service to ensure it is running:bashCopy codesudo systemctl status chronyd If everything is set up correctly, you should see output indicating that the service is active and running.

Now, Chrony is installed and running on your CentOS system. You can configure Chrony by editing its configuration file located at /etc/chrony.conf. After making any changes to the configuration file, remember to restart the Chrony service:

bashCopy code

sudo systemctl restart chronyd

Make sure to adjust any firewall settings if necessary to allow NTP (Network Time Protocol) traffic if you want your system to synchronize its time with remote NTP servers.

Configure DHCP Failover on CentOS 7

Configuring DHCP (Dynamic Host Configuration Protocol) failover on CentOS 7 typically involves using the ISC DHCP server, which is a widely used DHCP server on Linux systems. DHCP failover ensures high availability and redundancy for DHCP services. Here’s a basic guide on how to set up DHCP failover on CentOS 7 using ISC DHCP:

Prerequisites:

  1. Install ISC DHCP Server: If you haven’t already installed the DHCP server, you can do so with the following command: sudo yum install dhcp

Configuration:

  1. Edit the DHCP Configuration File: Open the DHCP configuration file in a text editor. The default configuration file is usually located at /etc/dhcp/dhcpd.conf.
  2. sudo vi /etc/dhcp/dhcpd.conf
  3. Configure DHCP Server: Add or modify the following lines in the dhcpd.conf file for the primary DHCP server. Replace the placeholders with your network-specific values.plaintextCopy codeauthoritative; subnet <your_subnet> netmask <your_netmask> { range <start_ip_address> <end_ip_address>; option routers <gateway_ip_address>; option domain-name-servers <dns_server_ip>; }
  4. Configure Failover: Add the following lines to enable DHCP failover. Replace the placeholders with appropriate values.plaintextCopy codefailover peer "dhcp-failover" { primary; address <primary_ip>; port 647; peer address <secondary_ip>; peer port 647; max-response-delay 60; max-unacked-updates 10; load balance max seconds 3; }
    • primary_ip: IP address of the primary DHCP server.
    • secondary_ip: IP address of the secondary DHCP server.
  5. Restart DHCP Server: After making the changes, restart the DHCP server for the configuration to take effect.bashCopy codesudo systemctl restart dhcpd

Secondary DHCP Server Configuration:

  1. Follow the same steps as above for configuring the DHCP server on the secondary server.
  2. Make sure to change the primary keyword to secondary in the failover configuration.

Verification:

  1. Check the DHCP server logs for any errors or warnings.bashCopy codesudo journalctl -u dhcpd
  2. Verify that the failover status is as expected.bashCopy codesudo dhcpd -t This command tests the configuration and reports any syntax errors.

Notes:

  • Ensure that both primary and secondary DHCP servers have synchronized configuration files.
  • Adjust the failover settings and subnet parameters according to your network requirements.
  • Regularly monitor DHCP server logs to catch any potential issues early on.

This guide provides a basic configuration for DHCP failover. Depending on your network architecture and requirements, you may need to adjust the configuration accordingly. Always test the failover setup in a controlled environment before deploying it in a production network.

How to Download Linux CentOS

Version Minor release CD and DVD ISO Images
CentOS-7 7.0.1406 For 32-bit & 64-bit   http://mirrors.nayatel.com/centos/7/isos/x86_64/
CentOS-6 6.6 For 32-bit   http://mirrors.nayatel.com/centos/6.6/isos/i386/
For 64-bit   http://mirrors.nayatel.com/centos/6.6/isos/x86_64/
CentOS-5 5.1 For 32-bit   http://mirrors.nayatel.com/centos/5.11/isos/i386/
For 64-bit   http://mirrors.nayatel.com/centos/5.11/isos/x86_64/