Changes

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In this chapter we will look in detail at the concept of security baselines in conjunction with the steps involved in hardening operating systems, networks and applications.

Domain Name Servers (DNS) provide the translation of human friendly names for network destination (such as a web site URL) to the IP addresses understood by routers and other network devices. Steps should be taken to ensure DNS software is updated regularly and that all access to servers is authenticated to prevent unauthorized zone transfers. Access to the server may be prevented by blocking port 53, or restricted by limiting access to the DNS server to one or more specified external systems.

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