Wildcards

Wildcards allow TCP Wrappers to more easily match groups of daemons or hosts. They are used most frequently in the client list field of access rules.

The following wildcards are available:

• ALL - Matches everything. It can be used for both the daemon list and the client list.

• LOCAL - Matches any host that does not contain a period (.), such as localhost.
• KNOWN - Matches any host where the hostname and host address are known or where the user is known.
• UNKNOWN - Matches any host where the hostname or host address are unknown or where the user is unknown.
• PARANOID - Matches any host where the hostname does not match the host address.

The KNOWN, UNKNOWN, and PARANOID wildcards should be used with care, because they rely on functioning DNS server for correct operation. Any disruption to name resolution may prevent legitimate users from gaining access to a service.