5.1. Securing Services With TCP Wrappers and xinetd
TCP wrappers provide access control to a variety of services. Most modern network services, such as SSH, Telnet, and FTP, make use of TCP wrappers, which stand guard between an incoming request and the requested service.
The benefits offered by TCP wrappers are enhanced when used in conjunction with xinetd, a super service that provides additional access, logging, binding, redirection, and resource utilization control.
It is a good idea to use IPTables firewall rules in conjunction with TCP wrappers and xinetd to create redundancy within service access controls. Refer to Chapter 7, Firewalls for more information about implementing firewalls with IPTables commands.
More information on configuring TCP wrappers and xinetd can be found in the chapter titled TCP Wrappers and xinetd in the Red Hat Enterprise Linux Reference Guide.
The following subsections assume a basic knowledge of each topic and focus on specific security options.