Linux Firewalld 基础实例

本次是一个Firewalld的基础操作实例，利用Firewalld图形操作界面进行访问控制操作。

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实验拓扑

需求分析

首先拓扑涉及到两个区域，这里使用work和public区域，分别做相应的规则。

1.work区域禁止icmp，允许192.168.100.101访问SSH服务，同时允许访问Apache服务。

2.public区域禁止icmp，禁止SSH服务，允许访问Apache服务。

分析方法：基于Firewalld的数据处理流程，可参考上一篇博客。

操作过程

基础准备

• server安装Apache服务，默认已存在SSH服务。

[root@server ~]# yum install -y httpd
[root@server ~]# echo "This is test page , all host can access" > /var/www/html/index.html
[root@server ~]# systemctl start httpd.service

• 默认不关闭防火墙的情况下，可以ping、ssh，不可以访问apache。

[root@host01 ~]# ping -c4 192.168.100.100
PING 192.168.100.100 (192.168.100.100) 56(84) bytes of data.
64 bytes from 192.168.100.100: icmp_seq=1 ttl=64 time=0.573 ms
64 bytes from 192.168.100.100: icmp_seq=2 ttl=64 time=0.575 ms
64 bytes from 192.168.100.100: icmp_seq=3 ttl=64 time=1.15 ms
64 bytes from 192.168.100.100: icmp_seq=4 ttl=64 time=0.441 ms

--- 192.168.100.100 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 0.441/0.686/1.156/0.277 ms

[root@host01 ~]# curl 192.168.100.100
curl: (7) Failed connect to 192.168.100.100:80; No route to host

[root@host01 ~]# ssh root@192.168.100.100
The authenticity of host '192.168.100.100 (192.168.100.100)' can't be established.
ECDSA key fingerprint is SHA256:5GGc1rmzWwjF+ozz/PPTyLO2s6NmFHSxbzCNsLazXhY.
ECDSA key fingerprint is MD5:0b:f5:62:d7:a4:1f:05:64:0b:7f:22:62:11:64:07:61.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.100.100' (ECDSA) to the list of known hosts.
root@192.168.100.100's password: 
Last login: Wed Oct 23 09:55:12 2019
[root@server ~]# logout
Connection to 192.168.100.100 closed.

配置 Firewalld

[root@server ~]# firewall-config

• 给work区域添加来源：192.168.100.101

• 允许work区域的http、ssh服务，禁止其他存在的服务

• 允许public区域的http服务，禁止其他存在的服务

• 通过ICMP过滤器禁止request请求，在两个区域都做。

结果验证

• 网站访问

[root@host01 ~]# curl 192.168.100.100
This is test page , all host can access

[root@host02 ~]# curl 192.168.100.100
This is test page , all host can access

• SSH远程

[root@host01 ~]# ssh root@192.168.100.100
root@192.168.100.100's password: 
Last login: Wed Oct 23 10:47:15 2019
[root@server ~]# logout
Connection to 192.168.100.100 closed.

[root@host02 ~]# ssh root@192.168.100.100
ssh: connect to host 192.168.100.100 port 22: No route to host

• ping测试

[root@host01 ~]# ping -c4 192.168.100.100
PING 192.168.100.100 (192.168.100.100) 56(84) bytes of data.
From 192.168.100.100 icmp_seq=1 Destination Host Prohibited
From 192.168.100.100 icmp_seq=2 Destination Host Prohibited
From 192.168.100.100 icmp_seq=3 Destination Host Prohibited
From 192.168.100.100 icmp_seq=4 Destination Host Prohibited

--- 192.168.100.100 ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 3001ms

[root@host02 ~]# ping -c4 192.168.100.100
PING 192.168.100.100 (192.168.100.100) 56(84) bytes of data.
From 192.168.100.100 icmp_seq=1 Destination Host Prohibited
From 192.168.100.100 icmp_seq=2 Destination Host Prohibited
From 192.168.100.100 icmp_seq=3 Destination Host Prohibited
From 192.168.100.100 icmp_seq=4 Destination Host Prohibited

--- 192.168.100.100 ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 3002ms

永久配置

• 设置永久配置

• 这里配置的是运行时配置，若要更改永久配置需点击选项，首先将Runtime设定为永久配置，然后重载防火墙，直接重载防火墙会丢失运行时的配置。

• 若是一开始就选择的永久配置，则可以直接重载防火墙使配置生效。