TCP wrappers add a measure of security for service daemons by standing between the daemon and incoming service requests. TCP wrappers log successful and unsuccessful connection attempts. Additionally, TCP wrappers can provide access control, allowing or denying the connection, depending on where the request originates. You can use TCP wrappers to protect daemons such as Secure Shell (SSH), Telnet, and the File Transfer Protocol (FTP). For information about TCP wrappers and sendmail, see the sendmail(1M) man page.
# inetadm -M tcp_wrappers=TRUE
For instructions, refer to the hosts_access (3) man page, which can be found in the /usr/sfw/man directory.