linux下防火墙常见命令（Centos7）
[root@localhost ~]# echo 查看防火墙状态
查看防火墙状态
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# systemctl status firewalld
鈼[0m firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: active (running) since Wed 2022-07-13 20:38:05 PDT; 1h 9min ago
Docs: man:firewalld(1)
Main PID: 8294 (firewalld)
CGroup: /system.slice/firewalld.service
鈹斺攢8294 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
Jul 13 20:38:05 localhost.localdomain systemd[1]: Starting firewalld - dynamic firewall daemon...
Jul 13 20:38:05 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.
Jul 13 20:38:06 localhost.localdomain firewalld[8294]: WARNING: /etc/sysconfig/network-scripts/ifcfg-ens33: Duplicate option definition: 'DNS1=114.114.114.114'
Jul 13 20:39:47 localhost.localdomain firewalld[8294]: WARNING: ALREADY_ENABLED: 8080:tcp
Jul 13 20:44:17 localhost.localdomain firewalld[8294]: WARNING: /etc/sysconfig/network-scripts/ifcfg-ens33: Duplicate option definition: 'DNS1=114.114.114.114'
[root@localhost ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: active (running) since Wed 2022-07-13 20:38:05 PDT; 1h 10min ago
Docs: man:firewalld(1)
Main PID: 8294 (firewalld)
CGroup: /system.slice/firewalld.service
└─8294 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
Jul 13 20:38:05 localhost.localdomain systemd[1]: Starting firewalld - dynamic firewall daemon...
Jul 13 20:38:05 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.
Jul 13 20:38:06 localhost.localdomain firewalld[8294]: WARNING: /etc/sysconfig/network-scripts/ifcfg-ens33: Duplicate option definition: 'DNS1=114.114.114.114'
Jul 13 20:39:47 localhost.localdomain firewalld[8294]: WARNING: ALREADY_ENABLED: 8080:tcp
Jul 13 20:44:17 localhost.localdomain firewalld[8294]: WARNING: /etc/sysconfig/network-scripts/ifcfg-ens33: Duplicate option definition: 'DNS1=114.114.114.114'
[root@localhost ~]# firewall-cmd --state
running
[root@localhost ~]# echo 关闭防火墙
关闭防火墙
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# firewall-cmd --state
not running
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# echo 开启防火墙
开启防火墙
[root@localhost ~]#
[root@localhost ~]# systemctl start firewalld
[root@localhost ~]# firewall-cmd --state
running
[root@localhost ~]#
[root@localhost ~]# echo 查看已开放外部访问的所有端口
查看已开放外部访问的所有端口
[root@localhost ~]#
[root@localhost ~]# firewall-cmd --zone=public --list-ports
8080/tcp 8080/udp 8098/tcp 111/tcp 25/tcp
[root@localhost ~]# echo 上述已开放tcp8080端口，udp 8080端口，tcp 111端口，tcp 25端口
上述已开放tcp8080端口，udp 8080端口，tcp 111端口，tcp 25端口
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# echo关闭端口，如关闭tcp 111端口
-bash: echo关闭端口，如关闭tcp: command not found
[root@localhost ~]#
[root@localhost ~]# firewall-cmd --zone=public --remove-port=111/tcp --permanent
success
[root@localhost ~]# echo 查看已开放外部访问的所有端口
查看已开放外部访问的所有端口
[root@localhost ~]# firewall-cmd --zone=public --list-ports
8080/tcp 8080/udp 8098/tcp 111/tcp 25/tcp
[root@localhost ~]# echo使得防火墙端口规则生效
-bash: echo使得防火墙端口规则生效: command not found
[root@localhost ~]# firewall-cmd --reload
success
[root@localhost ~]# firewall-cmd --zone=public --list-ports
8080/tcp 8080/udp 8098/tcp 25/tcp
[root@localhost ~]# echo 111端口已禁用
111端口已禁用
[root@localhost ~]# echo开启端口，如开启tcp 111端口
-bash: echo开启端口，如开启tcp: command not found
[root@localhost ~]# echo 开启端口，如开启tcp 111端口
开启端口，如开启tcp 111端口
[root@localhost ~]# firewall-cmd --zone=public --add-port=111/tcp --permanent
success
[root@localhost ~]# firewall-cmd --reload
success
[root@localhost ~]# firewall-cmd --zone=public --list-ports
8080/tcp 8080/udp 8098/tcp 25/tcp 111/tcp
[root@localhost ~]# echo 111端口tcp已可访问
111端口tcp已可访问
[root@localhost ~]# echo 查看端口使用情况
查看端口使用情况
[root@localhost ~]# netstat -lnpt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1/systemd
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 7418/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 7812/master
tcp6 0 0 :::111 :::* LISTEN 1/systemd
tcp6 0 0 :::22 :::* LISTEN 7418/sshd
tcp6 0 0 ::1:25 :::* LISTEN 7812/master
[root@localhost ~]# echo 查看指定进程信息
查看指定进程信息
[root@localhost ~]# ps
PID TTY TIME CMD
8223 pts/0 00:00:00 bash
13479 pts/0 00:00:00 ps
[root@localhost ~]# ps 1
PID TTY STAT TIME COMMAND
1 ? Ss 0:03 /usr/lib/systemd/systemd --switched-root --system --deserialize 22
[root@localhost ~]# ps 7418
PID TTY STAT TIME COMMAND
7418 ? Ss 0:00 /usr/sbin/sshd -D
[root@localhost ~]# echo 上述为ps pid查看
上述为ps pid查看