Welcome to this guest article. We will introduce two important configuration files in the Ubuntu operating system - /etc/hosts and /etc/sysctl in detail, and provide optimization guidelines. By properly configuring these two files, you can improve system performance, improve network connections, and strengthen system security, etc.
Reference:
https://www.howtouseubuntu.com/filesystem/understanding-ubuntu-etc-sysctl-conf-file/
Key point 1: Optimizing the /etc/hosts file
- Description: The /etc/hosts file is used for local host name resolution, where you can configure the mapping between static IP addresses and domain names.
- Example: Edit the /etc/hosts file to add a new domain name resolution.
- Application case: By mapping the local host with the IP address of important internal servers, DNS queries are reduced and network connection speed is improved.
Key point 2: Improve network connection performance
- Description: Adjust the /proc/sys/net/ipv4/tcp_keepalive_time parameter to optimize the TCP connection keeping time.
- Example: Use the sysctl command to set the value of the tcp_keepalive_time parameter.
- Application case: reduce dead connections, release inactive TCP connections, and improve system network connection performance.
Key point three: prevent DDoS attacks
- Description: Limit the SYN queue size of the Linux system to increase the ability to resist DDoS attacks.
- Example: Use the sysctl command to adjust the /proc/sys/net/ipv4/tcp_max_syn_backlog parameter.
- Application case: In the face of SYN Flood attacks, increase the size of the SYN queue to prevent network services from being unavailable.
Key point 4: Optimize memory usage
- Description: Adjust the /proc/sys/vm/swappiness parameter to control memory swap behavior and reduce swap operations.
- Example: Use the sysctl command to set the value of the vm.swappiness parameter.
- Application case: reduce memory exchange frequency, reduce system performance degradation, and improve overall performance.
Key point five: Strengthen network security
- Description: Enhance the security of TCP SYN Cookies by configuring the /proc/sys/net/ipv4/tcp_syncookies parameter.
- Example: Use the sysctl command to enable TCP SYN Cookies.
- Application case: When faced with SYN Flood attacks, enable TCP SYN Cookies to prevent attackers from consuming system resources and protect network connections.
Hope this article can provide you with practical guidance on optimizing hosts file and sysctl parameters on Ubuntu system. While understanding these key points, you can apply it more flexibly to the actual production environment to improve system performance and security.
Thank you for reading, I hope you can gain useful knowledge and practical experience from it!
We have compiled a pdf file of Linux learning, put it in the following path, you can mention it yourself: https://www.howtouselinux.com/post/linux-commands-for-linux-beginners-cheat-sheet