linux远程访问权限控制(hosts.allow和hosts.deny)

linux远程访问权限控制(hosts.allow和hosts.deny)

/etc/hosts.allow和/etc/hosts.deny两个文件是控制远程访问设置的，通过他可以允许或者拒绝某个ip或者ip段的客户访问linux的某项服务。

比如SSH服务，我们通常只对管理员开放，那我们就可以禁用不必要的IP，而只开放管理员可能使用到的IP段。

使用：

修改/etc/hosts.allow文件

#
# 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:210.13.218.*:allow
sshd:222.77.15.*:allow
以上写法表示允许210和222两个ip段连接sshd服务（这必然需要hosts.deny这个文件配合使用），当然:allow完全可以省略的。

当然如果管理员集中在一个IP那么这样写是比较省事的

all:218.24.129.110//他表示接受110这个ip的所有请求！

/etc/hosts.deny文件，此文件是拒绝服务列表，文件内容如下：

#
# 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:deny


注意看：sshd:all:deny表示拒绝了所有sshd远程连接。:deny可以省略。

所以：当hosts.allow和 host.deny相冲突时，以hosts.allow设置为准。

注意修改完后：

service xinetd restart

才能让刚才的更改生效。





Linux下防止未授权IP使用ssh服务

方法一

iptables -A INPUT -p tcp -s 192.168.0.0/24 --destination-port 22 -j ACCEPT

iptables -A INPUT -p tcp -s 192.168.1.0/24 --destination-port 22 -j ACCEPT

iptables -A INPUT -p tcp -s ! 127.0.0.1 --destination-port 22 -j DROP

方法二

[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!

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.

#

sshd: 192.168.0.230 :allow

这里写允许的ip或者网段