Linux Administration Videos | Session - 31 | BOOTING PROCESS & DNS | by Madhuri Madam

Step-by-Step Tutorial: Understanding the Booting Process and Configuring DNS

1. Understanding the Booting Process:

   • The booting process in Linux involves six stages: BIOS, Master Boot Record (MBR), Unified Boot Loader (GRUB), Kernel, Init, and Run Levels.
   • BIOS (Basic Input Output System) is the first stage that checks hardware components when the computer is switched on.
   • MBR is responsible for loading and executing bootloaders and is located in the first sector of the bootable disk.
   • GRUB is the bootloader for Linux systems that displays information about multiple operating systems installed.
   • Kernel acts as an interface between the shell and hardware, controlling the system's functions.
   • Init files contain run level programs that determine the system's behavior based on the run level.

2. Configuring DNS (Domain Name System):

   • DNS is used to convert IP addresses to domain names and vice versa for easier communication.
   • To configure DNS, ensure the bind and cache packages are installed.
   • Modify the configuration files /etc/named.conf and /etc/named.rfc1912.zones to set up DNS settings.
   • Add your domain name and IP address information in the configuration files to create DNS entries.
   • Update the DNS service by restarting it using the command service named restart.

3. Troubleshooting DNS and Testing Configuration:

   • To troubleshoot DNS issues, understand the concepts of PTR (Pointer Record), NS (Name Server), and AAAA (IPv6 Address).
   • Check the DNS configuration by editing the /etc/resolv.conf file and adding the necessary DNS entries.
   • Verify the DNS setup by using commands like dig domain_name and dig -x IP_address to ensure proper resolution.

4. Finalizing and Testing:

   • After configuring DNS, test the setup by accessing your configured domain name in a web browser.
   • Use commands like dig domain_name and dig -x IP_address to confirm the DNS resolution.
   • Ensure that the local DNS server correctly resolves domain names to IP addresses and vice versa.

5. Additional Notes and Resources:

   • Review the provided slides and notes for a detailed understanding of the booting process and DNS configuration.
   • For any further assistance or questions related to Linux administration, reach out for support and guidance.

By following these steps, you can gain a practical understanding of the booting process in Linux and effectively configure DNS settings for your local environment. Feel free to practice these concepts and troubleshoot any issues that may arise during the process.