/etc/hosts.allow
위 두파일을 수정해 줘야 함
_hosts.deny
:#
# hosts.deny This file describes the names of the hosts which are
*not* allowed to use the local INET services, as decided
by the '/usr/sbin/tcpd' server.
#
# The portmap line is redundant, but it is left to remind you that
# the new secure portmap uses hosts deny and hosts.allow, in particular
# you should know that NFS uses portmap!
sshd : ALL
_hosts.allow
:#
#
# 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.
sshd : 222.222.222. :ALLOW -------->특정대역만 허용
sshd : 222.222.222.222 :ALLOW ---->특정 ip만 허용