The TCP Wrappers package is installed by default on Fedora Linux and provides host-based security separate from that provided by a firewall running on the server itself or elsewhere.
The application relies on two main files:
/etc/hosts.allow: Defines the hosts and networks allowed to connect to the server. The TCP Wrappers enabled application searches this file for a matching entry, and if it finds one, then the connection is allowed.
/etc/hosts.deny: Defines the hosts and networks prohibited from connecting to the server. If a match is found in this file, the connection is denied. No match means the connection proceeds normally.
The /etc/hosts.allow file is always read first and both files are always read from top to bottom, therefore the ordering of the entries is important.
The application relies on two main files:
/etc/hosts.allow: Defines the hosts and networks allowed to connect to the server. The TCP Wrappers enabled application searches this file for a matching entry, and if it finds one, then the connection is allowed.
/etc/hosts.deny: Defines the hosts and networks prohibited from connecting to the server. If a match is found in this file, the connection is denied. No match means the connection proceeds normally.
The /etc/hosts.allow file is always read first and both files are always read from top to bottom, therefore the ordering of the entries is important.