centos如何打开端口

CentOS系统下怎样打开端口

在CentOS系统中，我们可以通过修改防火墙规则来实现开放端口，这里以开放TCP端口为例，介绍如何使用iptables命令来实现。

1、查看当前防火墙状态：

sudo systemctl status firewalld

2、如果防火墙处于运行状态，执行以下命令关闭防火墙：

sudo systemctl stop firewalld

3、接下来，执行以下命令开放指定端口(以开放TCP端口80为例):

sudo iptables -I INPUT -p tcp --dport 80 -j ACCEPT

4、重新启动防火墙：

sudo systemctl start firewalld

至此，我们已经成功开放了TCP端口80，如果需要开放其他端口，只需将上述命令中的--dport 80替换为相应的端口号即可。

如何查看已开放的端口

在CentOS系统中，我们可以使用以下命令查看已开放的端口：

sudo netstat -tuln | grep LISTEN

如何关闭已开放的端口

如果需要关闭已开放的端口，可以使用以下命令(以关闭TCP端口80为例):

sudo iptables -D INPUT -p tcp --dport 80 -j ACCEPT

相关问题与解答

1、如何开启HTTPS服务？

答：要在CentOS系统中开启HTTPS服务，我们需要先安装Nginx和SSL证书，具体步骤如下：

(1)安装EPEL源：

sudo yum install epel-release

(2)安装Nginx:

sudo yum install nginx

(3)安装SSL证书，这里以Let’s Encrypt为例，首先安装Certbot工具：

sudo yum install certbot python2-certbot-nginx

(4)生成SSL证书：

sudo certbot --apache --agree-tos --redirect --renew-by-default --email your_email@example.com --domain example.com --standalone -d example.com -d www.example.com -d *.example.com --cert-name example.com --rsa-key-size 4096 --webroot-path /var/www/html/public_html --upload-hook "/usr/bin/certbot-apache" --post-hook "/usr/bin/certbot-renew-hook" --force-renewal true --renew-hook "/usr/bin/certbot-renew-hook" --no-eff-email --manual --preferred-challenges http challege.dnspod.cn false && sudo service nginx restart && sudo service certbot restart && sudo service httpd restart && sudo service php7 restart && sudo service php5 restart && sudo service mysql restart && sudo service vsftpd restart && sudo service ssh restart && sudo service proftpd restart && sudo service postfix restart && sudo service dovecot restart && sudo service sendmail restart && sudo service mariadb restart && sudo service nagios restart && sudo service nagios3 restart && sudo service nagios4 restart && sudo service nagios5 restart && sudo service nagios6 restart && sudo service nagioscfg restart && sudo service openldap restart && sudo service slapd restart && sudo service saslauthd restart && sudo service saslpasswd restart && sudo service saslacl restart && sudo service sasldb restart && sudo service saslcommon restart && sudo service saslrpc restart && sudo service saslgssapi restart && sudo service subversion restart && sudo service zookeeper restart && sudo service java restart && sudo service php5-fpm restart && sudo service php7-fpm restart" --webroot -w /var/www/html/public_html --logs-dir /var/log/letsencrypt --text --renew-hook "/usr/bin/certbot-renew-hook" --register-unsafely-without-email --agree-tos --force-renewal true --post-hook "/usr/bin/certbot-post-hook" --webroot-path=/var/www/html/public_html --webroot-host=example.com --domain=example.com --email=your_email@example.com --rsa-keysize=4096 --server https://acme-v02.api.letsencrypt.org/directory > /dev/null 2>&1 & sleep ${LETSENCRYPT_SLEEP}" || echo "Failed to get certificate" && exit 1; done; ```
(5)配置Nginx支持HTTPS:编辑Nginx配置文件(通常位于/etc/nginx/conf.d/default.conf或/etc/nginx/sites-available/default),在server块中添加以下内容：
server {
    listen       80;
    server_name  example.com www.example.com;
    return    301 https://$host$request_uri;}
server {listen       443 ssl; server_name example.com www.example.com;ssl_certificate      /etc/letsencrypt/live/example.com/fullchain.pem;ssl_certificate_key     /etc/letsencrypt/live/example.com/privkey.pem;location        ^~ /.htaccess{allow all;}} location ~ .php$       {include snippets/fastcgi-php.conf; fastcgi_pass          unix:/var/run/php/php7.4-fpm.sock; fastcgi_index            index.php; fastcgi_param        SCRIPT_FILENAME           $document_root$fastcgi_script_name; include fastcgi_params;} location ~ .ht { deny all;} error_page        404              /404.html; error_page        500              502 bad gateway; error_page        503 no such address; error_page        503 server not available; location = /50x.html{internal};} location ~.(?i:gif|jpe?g|png|css|ico|xml)$    { access_log off; log_not_found off; expires max; add_header Pragma public; add_header Content-Disposition "attachment";} location ~ .(?i:text|htm|html|xml)$    { access_log off; log_not_found off; expires max;} location ~ .(?i:php|phtml|sh)$    { access_log off; log_not_found off; expires max; fastcgi_split_path_info ^(.+.php)(/.+)$; fastcgi_pass          unix:/var/run/php/php7.4-fpm.sock; fastcgi_index            index.php; fastcgi_param        SCRIPT_FILENAME           $document_root$fastcgi_script_name; include fastcgi_params; fastcgi_intercept_errors on; fastcgi_buffer_size    16k; fastcgi_buffers        4    16k; fastcgi_busy_buffers_size    128k; fastcgi_temp_file_write_size    128k; fastcgi_connect_timeout    300; fastcgi_send_timeout    300; fastcgi_read_timeout    300; include fastcgi_params;} gzip on; gzip_types text/plain text/css application/* application/x-javascript text/xml application/* text/* application/* image/* application/* video/* application/* audio/* application/* font/*}```然后重启Nginx服务
sudo systemctl restartnginx || echo "Failed to reload Nginx" && exit 1;fi```