Tcpwrapper

#
# hosts.allow   This file describes the names of the hosts which are
#               allowed to use the local INET services, as decided
#               by the '/usr/sbin/tcpd' server.
#
ALL: 127.0.0.0/255.0.0.0
in.rshd: 172.31.173.64/255.255.255.224
portmap: 172.31.165.0/255.255.255.0,172.31.168.0/255.255.254.0,172.28.130.224/255.255.255.0
sshd: 172.0.0.0/255.0.0.0: ALLOW
in.telnetd: 172.0.0.0/255.0.0.0: ALLOW
statd: 172.31.165.0/255.255.255.0,172.31.168.0/255.255.254.0
gdm: 172.31.128.0/255.255.252.0, 172.31.132.0/255.255.252.0
kdm: 172.31.128.0/255.255.252.0, 172.31.132.0/255.255.252.0
authd: 172.0.0.0/255.0.0.0
in.authd: 172.0.0.0/255.0.0.0