Implementing DNS in the Enterprise
When you installed Active Directory in Chapter 4, you created a single DNS server on DC1. When you added a replica DC, DC2, and the child domain with UKDC1, you did not set up any additional DNS server in your forest. You always want to configure your clients and servers to use at least two DNS servers. In an enterprise organization, this is a best practice. For servers with a static DNS setting, you should also update the DHCP DNS server option settings to ensure that your DHCP servers provide two DNS server entries to DHCP clients.
In most organizations, there are several DNS service configuration options you may wish to set. These include whether to allow DNS server recursion on the server, the maximum size of the DNS cache, and whether to use Extended DNS (EDNS).
EDNS (also referred to as EDNS0 or, more recently, EDNS(0)) is an extension mechanism that enables more recent DNS servers to interact with older servers that may not be capable...
