 portmap.   portmap    ,  -
        , ,   
     .    -
   portmap       
 /etc/hosts. allow  /etc/hosts.deny (.   " -
 ").    hosts, deny  , 
   portmap    ():

portmap: ALL
          :

$ rpcinfo -p _
No remote programs registered.     (   )

 _   ,     
hosts, deny.    ;    -
  .
    hosts. allow     :

portmap: 1_

 1_  IP-   ,     
 rpcinfo.    portmap   hosts, allow  IP-;

   ,  portmap, ,   .
     rpcinfo,     , 
RPC,     portmap.      "-
 "  21.

 .   portmap    -
   .      ,  -
  DoS- (. )  .

 xinetd

 xinetd       inetd, -
    4.3BSD.  Internet  -
  ,   ,      
   (.  ""  12)     . -
 xinetd        -
   .

 xinetd,   Red Hat Linux,   libwrap.a, -
        /etc/hosts. allow 
/etc/hosts.deny (     ). -
  TCP   ,    -
   xinetd.

   xinetd    /etc/xinetd.conf.  -
  ,  Red Hat:

$ cat /etc/xinetd.conf

# Simple configuration file for xinetd
(    xinetd)

 11.  :                     425