only_from        determines the remote hosts to  which  the  particular
                        service  is  available.   Its  value  is  a list of IP
                        addresses which can be specified in any combination of
                        the following ways:
                        a)   a  numeric address in the form of %d.%d.%d.%d. If
                             the rightmost components are 0, they are  treated
                             as  wildcards  (for example, 128.138.12.0 matches
                             all hosts on  the  128.138.12  subnet).
                        [..]
                        Specifying this attribute without a  value  makes  the
                        service available to nobody.
	> cat /etc/xinetd.d/swat
# SWAT is the Samba Web Administration Tool.
service swat
{
        socket_type     = stream
        protocol        = tcp
        wait            = no
        user            = root
        server          = /usr/sbin/swat
        only_from       =  127.0.0.1 192.168.42.0 10.0.0.0
        log_on_failure  += USERID
}
	> cat /etc/xinetd.d/swat 
# SWAT is the Samba Web Administration Tool. 
service swat 
{ 
        socket_type     = stream 
        protocol        = tcp 
        wait            = no 
        user            = root 
        server          = /usr/sbin/swat 
        only_from       =  127.0.0.1 192.168.42.0 10.0.0.0 
        log_on_failure  += USERID 
}