利用tcpwrapper限制ssh服务的登录

[root@nihao ~]# more /etc/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!
# 下面是拒绝所有的ssh服务连接
sshd: ALL : deny
[root@nihao ~]# more /etc/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.

#
# 这里写允许的ip或者网段
sshd: 192.168.0.230 :allow