David Cao

David Cao

David is a Cloud & DevOps Enthusiast. He has years of experience as a Linux engineer. He had working experience in AMD, EMC. He likes Linux, Python, bash, and more. He is a technical blogger and a Software Engineer. He enjoys sharing his learning and contributing to open-source.

Filtering DNS with Tcpdump on Port 53

If you’re a Linux system administrator, then you’re probably familiar with DNS, which is a critical component of networking.  TCPdump is a powerful Linux command that can help you capture and filter network packets. With TCPdump, you can analyze DNS…

3 Ways to make Top Command sort by Memory

Top is a very powerful command to periodically display a sorted list of system processes. The default sorting key is %CPU on Linux. Below we collect 3 ways to sort processes by memory. Understanding top command in Linux The top…

Filtering ICMP Packets with Tcpdump

Tcpdump command in Linux can be used to capture ICMP packets. We will start with ICMP protocol introduction and then check out how to filter ICMP and ICMPv6 packets with tcpdump command. What is ICMP? ICMP is short for Internet…

Linux Memory Metrics: /proc/meminfo

/proc/meminfo on Linux displays current system-wide memory performance statistics. It provides the most complete view of system memory usage. Here is a detailed explanation of all the metrics. We can use these memory metrics to troubleshoot Linux memory issues. Related:…

How Userdel Works In Linux

Userdel command can be used to delete a user and related files in Linux. In most Linux distributions, the user home and mail spool directories are not removed when removing a user account with userdel. We are going through the…

4 ways to use Linux tar Command

The tar command in Linux is used to bundle up multiple files and/or directories. It’s similar to the zip command. However, zip files are compressed by definition; tar files can be compressed, but don’t have to be. How to Use…

How tar works in Linux

The tar command in Linux is used to bundle up multiple files and/or directories. It’s similar to the zip command. However, zip files are compressed by definition; tar files can be compressed, but don’t have to be. How tar Works…