Linux server security: learn the use and management of essential commands

Linux server security: learn the use and management of essential commands

With the rapid development of the Internet, the use of Linux servers is becoming more and more widespread, and the security of servers Sex also became an extremely important issue. In this article, we will explore some must-learn Linux commands to harden and manage server security. This article will introduce you to some common security commands and provide corresponding code examples for better understanding.

1. View log files

In the security management of the server, viewing log files is a very important task. By analyzing log files, administrators can track system activity, detect potential security issues, and quickly take necessary action. The following are some commonly used commands to view log files:

• View system log files: tail /var/log/syslog
• View authentication log files:tail /var/log/auth.log
• View the Web server access log file: tail /var/log/apache2/access.log

Through the above command, the administrator can view the latest content of the log file in real time, or use the grep command to search for specific keywords.

2. Firewall Management

Firewall is one of the key components to protect the server from malicious attacks. The following are some common commands for firewall management:

• View the firewall status: sudo ufw status
• Enable the firewall: sudo ufw enable
• Disable the firewall: sudo ufw disable
• Allow specific port access: sudo ufw allow 22 (Allow SSH access)

Administrators can configure firewall rules as needed to control inbound and outbound network traffic and ensure server security.

3. Security Update Management

Regularly updating software and operating system patches on your server is critical to server security. Here are some common commands for security update management:

• Update package list: sudo apt update
• Install security updates: sudo apt upgrade
• Check available security updates:sudo apt list --upgradable

By executing the above command, the administrator can obtain the latest updates in a timely manner Security updates and ensuring that the server’s software and operating system are kept up to date.

4. File and directory permission management

Correct file and directory permission settings are an important part of server security. The following are some commonly used commands for file and directory permission management:

• Change file owner:sudo chown owner:group file
• Change file permissions :sudo chmod permissions file
• Change directory permissions:sudo chmod permissions directory

Manage with appropriate file and directory permission settings Administrators can ensure that only authorized users have access to sensitive files and directories and prevent unauthorized access.

5. Password Policy Management

A strong password policy is an important factor in protecting server security. The following are some common commands for password policy management:

• Set password policy: sudo passwd -l username (Lock user)
• Check password policy Requirements: sudo grep "password" /etc/pam.d/common-password

Administrators can set password policies according to actual needs, such as password length requirements and password expiration time etc. to enhance the password security of the server.

Conclusion

By learning and mastering the Linux commands mentioned above, administrators can better manage and enhance server security. Of course, these are just entry-level security commands. More in-depth server security knowledge requires continuous learning and practice. Maintaining timely updates, regular backups, and continually strengthening your server's security are important steps to ensuring your server is secure.

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