Linux防火墙配置001

        Linux防火墙主要用于控制网络流量，保护系统安全。在Linux中，有几种不同的防火墙管理工具，其中最常见的是iptables和firewalld。本章主要讲述如何关闭防火墙。

操作系统：

CentOS Stream 9

操作步骤：

关闭防火墙，selinux  ,22行    SELINUX=disabled   

​
[root@localhost ~]# cat -n /etc/sysconfig/selinux
     1	
     2	# This file controls the state of SELinux on the system.
     3	# SELINUX= can take one of these three values:
     4	#     enforcing - SELinux security policy is enforced.
     5	#     permissive - SELinux prints warnings instead of enforcing.
     6	#     disabled - No SELinux policy is loaded.
     7	# See also:
     8	# http://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/using_selinux/changing-selinux-states-and-modes_using-selinux#changing-selinux-modes-at-boot-time_changing-selinux-states-and-modes
     9	#
    10	# NOTE: Up to RHEL 8 release included, SELINUX=disabled would also
    11	# fully disable SELinux during boot. If you need a system with SELinux
    12	# fully disabled instead of SELinux running with no policy loaded, you
    13	# need to pass selinux=0 to the kernel command line. You can use grubby
    14	# to persistently set the bootloader to boot with selinux=0:
    15	#
    16	#    grubby --update-kernel ALL --args selinux=0
    17	#
    18	# To revert back to SELinux enabled:
    19	#
    20	#    grubby --update-kernel ALL --remove-args selinux
    21	#
    22	SELINUX=disabled    此处注意
    23	# SELINUXTYPE= can take one of these three values:
    24	#     targeted - Targeted processes are protected,
    25	#     minimum - Modification of targeted policy. Only selected processes are protected.
    26	#     mls - Multi Level Security protection.
    27	SELINUXTYPE=targeted
    28	
29	
​
[root@localhost ~]# cat -n /etc/selinux/config
     1	
     2	# This file controls the state of SELinux on the system.
     3	# SELINUX= can take one of these three values:
     4	#     enforcing - SELinux security policy is enforced.
     5	#     permissive - SELinux prints warnings instead of enforcing.
     6	#     disabled - No SELinux policy is loaded.
     7	# See also:
     8	# http://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/using_selinux/changing-selinux-states-and-modes_using-selinux#changing-selinux-modes-at-boot-time_changing-selinux-states-and-modes
     9	#
    10	# NOTE: Up to RHEL 8 release included, SELINUX=disabled would also
    11	# fully disable SELinux during boot. If you need a system with SELinux
    12	# fully disabled instead of SELinux running with no policy loaded, you
    13	# need to pass selinux=0 to the kernel command line. You can use grubby
    14	# to persistently set the bootloader to boot with selinux=0:
    15	#
    16	#    grubby --update-kernel ALL --args selinux=0
    17	#
    18	# To revert back to SELinux enabled:
    19	#
    20	#    grubby --update-kernel ALL --remove-args selinux
    21	#
    22	SELINUX=disabled    #注意
    23	# SELINUXTYPE= can take one of these three values:
    24	#     targeted - Targeted processes are protected,
    25	#     minimum - Modification of targeted policy. Only selected processes are protected.
    26	#     mls - Multi Level Security protection.
    27	SELINUXTYPE=targeted
    28	
29	

​


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firewalld

[root@localhost ~]# systemctl disable firewalld
[root@localhost ~]# 
[root@localhost ~]# 
[root@localhost ~]# 
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# 

重启服务器

[root@localhost ~]#reboot

查询防火墙是否关闭

[root@localhost ~]# sestatus
SELinux status:                 disabled
[root@localhost ~]# systemctl status firewalld
○ firewalld.service - firewalld - dynamic firewall daemon
     Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; preset: >
     Active: inactive (dead)
       Docs: man:firewalld(1)
[root@localhost ~]# iptables -vnL
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
[root@localhost ~]#