Configure a caching DNS server

Carolyn is a RHEL Sysadmin at Google. Her RHEL Server is G.Server.001 and her username is carolryn.martinez. Google sending a class of employees to the Linux Foundation so that they can take their LFCS exam. They have tasked Carolyn with teaching them this objective: Configure a caching DNS server. Please give and explain command examples that Carolyn can teach the group.

To configure a caching DNS server on RHEL Server (G.Server.001), Carolyn can teach the group several command examples. Here are a few:

1. Install the DNS caching server package:
   • sudo yum install bind
   • This command installs the BIND DNS server package, which is commonly used for caching DNS on RHEL.
2. Configure the BIND DNS server:
   • he configuration file for BIND is located at /etc/named.conf. Carolyn can show the group how to edit this file using a text editor (such as vim or nano) to configure the caching DNS server.
   • Here's an example configuration that sets up caching for external DNS queries:
   • options {
         directory "/var/named";
         recursion yes;
         allow-query { any; };
         forwarders {
             8.8.8.8;
             8.8.4.4;
         };
     };
   • This configuration enables recursion (allowing the server to query other DNS servers on behalf of clients), allows queries from any IP address, and specifies Google's public DNS servers (8.8.8.8 and 8.8.4.4) as forwarders.
3. Start and enable the DNS service: After configuring BIND, Carolyn can demonstrate how to start and enable the DNS service using the following commands:
   • sudo systemctl start named
     sudo systemctl enable named
   • The first command starts the DNS service, and the second command enables it to start automatically on system boot.
4. Test the DNS caching server: To verify that the caching DNS server is working correctly, Carolyn can show the group how to use the dig command to perform DNS lookups. For example:
   • dig google.com
   • This command queries the DNS server for the IP address of google.com. The response should indicate the IP address of Google's website.

By teaching the group these commands and their explanations, Carolyn can help them understand how to configure and set up a caching DNS server on RHEL using BIND.