Learn how to install and configure a secondary DNS server in Linux using Ubuntu 22.04.1 LTS and Bind 9. Follow step-by-step instructions to update and configure an existing primary DNS server for internal zone transfers, install and set up a secondary server as a redundant forwarder for Internet DNS resolution, and perform client testing. Explore topics such as updating primary server software, configuring primary and secondary servers, initial testing, restricting access, configuring DNS forwarding, updating DNS client settings, and testing DNS resolution and transfers. Gain practical knowledge on implementing DNS redundancy while understanding the importance of maintaining an up-to-date primary server for future DNS changes.