Understand Linux server security: essential knowledge and skills
With the continuous development of the Internet, Linux servers are increasingly used in various fields. However, since servers store a large amount of sensitive data, their security issues have also become the focus of attention. This article will introduce some essential Linux server security knowledge and skills to help you protect your server from attacks.
sudo yum update
In Ubuntu, we can use the following command to perform the update operation:
sudo apt-get update
The following example demonstrates how to add users and assign permissions:
sudo useradd -m -s /bin/bash newuser # 添加用户 sudo passwd newuser # 设置用户密码 sudo usermod -aG sudo newuser # 将用户加入sudo组,授予管理员权限
sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT # 允许SSH连接 sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT # 允许HTTP连接 sudo iptables -A INPUT -j DROP # 其他流量全部拒绝
First, generate the public and private keys locally:
ssh-keygen -t rsa -b 4096
Then, copy the public key to ~/ on the server. In the ssh/authorized_keys file:
cat ~/.ssh/id_rsa.pub | ssh user@server 'cat >> ~/.ssh/authorized_keys'
Finally, use the private key to log in to the server:
ssh -i ~/.ssh/id_rsa user@server
tail -f /var/log/auth.log # 实时监控认证日志 grep "Failed password" /var/log/auth.log # 查找登录失败的记录
Summary
Protecting Linux server security is a basic task for every server administrator. This article introduces some essential Linux server security knowledge and skills, including updating and maintaining the operating system and software, user and permission management, configuring firewalls, using keys to log in and monitoring log files, etc. By learning and practicing these knowledge and skills, we can better protect our servers from attacks and ensure the security of our data.
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