      ,  -
  hosts, allow  hosts, deny   .  -
  ,      .

1.   -     hosts, allow,  -
.

2.   -     hosts, deny,  -
.

3.          hosts, allow  hosts, deny,
 .

    hosts, allow  hosts, deny  ,   -
..     ,        -
,   .

.        hosts, deny 
,    :

$ cat /etc/hosts.deny

ALL : ALL : echo '4    %d  ' 
/var/log/tcpwrappers.log

         , 
 ,    hosts, allow.   
     /var/log/tcpwrappers. log.  % -
    , a %d    ,    -
 .

     hosts, deny     
hosts, allow         . -
,   hosts, allow      OpenSSH
(ssh, scp, sftp),    telnet    ,   -
  ,      192.168.:

$ cat /etc/hosts.allow

sshd : ALL

in.telnet : LOCAL

in.telnet : 192.168.? 127.0.0.1

        sshd    (ALL).
          ,  
 (LOCAL).     , IP-  -
  192.168.,   .

   chroot

   UNIX       . 
  UNIX,    Linux,    
  .  chroot      -
,   /.

428  IV.  