To restrict access to your Unix or Linux machine, you must modify the
\n\/etc\/hosts.allow and \/etc\/host.deny files. These files are used by the
\ntcpd (tcp wrapper) and sshd programs to decide whether or not to accept
\na connection coming in from another IP address. Restrict access to only
\nthose network addresses you are certain should be allowed access. The
\nfollowing two example files allow connections from any address in the
\ncracker.com network domain, but no others.<\/p>\n
\/etc\/hosts.allow<\/p>\n
Using the configuration shown in the following \/etc\/hosts.allow file, to
\npermit connections to any services protected by the tcpd or sshd from
\nonly systems within the virginia.edu domain:<\/p>\n
#
\n# hosts.allow This file describes the names of the hosts which are
\n# allowed to use the local INET services, as decided
\n# by the \u00e2\u20ac\u02dc\/usr\/sbin\/tcpd\u00e2\u20ac\u2122 server.
\n#
\n# Only allow connections within the virginia.edu domain.<\/p>\n
ALL: .cracker.com<\/p>\n
\/etc\/hosts.deny<\/p>\n
Suggested: \/etc\/hosts.deny file content. With this configuration, access
\nto your machine from all hosts is denied, except for those specified in
\nhosts.allow.<\/p>\n
#
\n# hosts.deny This file describes the names of the hosts which are
\n# *not* allowed to use the local INET services, as
\ndecided
\n# by the \u00e2\u20ac\u02dc\/usr\/sbin\/tcpd\u00e2\u20ac\u2122 server.
\n#
\n# deny all by default, only allowing hosts or domains listed in
\nhosts.allow.<\/p>\n
ALL: ALL<\/p>\n