TCP Wrappers and xinetd.
Controlling access to network services is one of the most important security tasks facing a server administrator. Fortunately, under Red Hat Linux there are a number of tools which do just that. For instance, an iptables -based firewall filters out unwelcome network packets within the kernel's network stack. For network services that utilize it, TCP wrappers add an additional layer of protection by defining which hosts are allowed or not allowed to connect to " wrapped " network services. One such wrapped network service is the xinetd super server . This service is called a super server because it controls connections to a subset of network services and further refines access control. This topic focuses on the role of TCP wrappers and xinetd in controlling access to network services and reviews how these tools can be used to enhance both logging and utilization management. TCP Wrappers The TCP wrappers package ( tcp_wrappers ) is installed by default unde...