服务器——那些年我踩过的坑

CentOS 7卸载firewalld防火墙命令

systemctl disable firewalld
systemctl stop firewalld
systemctl mask firewalld
systemctl disable firewalld.service

腾讯云

卸载云镜

/usr/local/qcloud/stargate/admin/uninstall.sh
/usr/local/qcloud/YunJing/uninst.sh
/usr/local/qcloud/monitor/barad/admin/uninstall.sh

原版bbr安装

安装脚本：

wget --no-check-certificate https://github.com/teddysun/across/raw/master/bbr.sh && chmod +x bbr.sh && ./bbr.sh

输入 uname-r 显示最新版内核的就安装成功了

在输入一下命令

sysctl net.ipv4.tcp_available_congestion_control

一般显示为

net.ipv4.tcp_available_congestion_control = bbr cubic reno
或者为：
net.ipv4.tcp_available_congestion_control = reno cubic bbr

甲骨文云

1.报错

[错误] /boot/grub2/grub.cfg 找不到，请检查.

解决办法

grub2-mkconfig -o /boot/grub2/grub.cfg

2. 卸载内置脚本

systemctl stop oracle-cloud-agent
systemctl disable oracle-cloud-agent
systemctl stop oracle-cloud-agent-updater
systemctl disable oracle-cloud-agent-updater

3. 防火墙

一般甲骨文云默认是开启防火墙的

(1). 查看防火墙状态

systemctl status firewalld.service

停止防火墙：

systemctl stop firewalld.service

(2). 直接卸载

systemctl disable firewalld
systemctl stop firewalld
systemctl mask firewalld
systemctl disable firewalld.service

(3). 端口开放(推荐)

开放1122端口

firewall-cmd --zone=public --add-port=1122/tcp --permanent

$关闭$ 1122端口

firewall-cmd --zone=public --remove-port=1122/tcp --permanent 

立即生效

firewall-cmd --reload

检查端口被哪个进程占用

netstat -lnpt |grep 1122

centos安装并且开启firewalld防火墙

1. 安装

yum install firewalld

ranho

# 开启服务
systemctl start firewalld.service
# 如果开启服务 报错 Failed to start firewalld.service: Unit is masked
# 以下命令取消对firewalld服务的锁定   下次需要锁定该服务时执行: systemctl mask firewalld
systemctl unmask firewalld

# 关闭防火墙
systemctl stop firewalld.service

# 开机自动启动
systemctl enable firewalld.service

Nginx 防御

防止 cc 以及ddos 攻击

# 限制ip每秒请求次数  加在http{}里面
 limit_req_zone $binary_remote_addr zone=allips:5m rate=20r/m;
 limit_conn_zone $binary_remote_addr zone=one:5m;

# 限制ip的连接数 以及速度
limit_conn one 3;
limit_req zone=allips burst=5 nodelay;
limit_rate 200k;