ICMP is a network layer protocol used by network devices to diagnose network communication issues. Tcpdump command on Linux can be used to capture network packets. We can use the following examples to capture ICMP and ICMPv6 packets with tcpdump…
Nethogs is a Linux command that allows us to view network usage of a running process in realtime. Nethogs sorts the output by process and network bandwidth usage. We can quickly find out which process is using more bandwidth. This…
This article is part of the following series. Iotop is an interactive real-time I/O usage monitoring tool to check disk read and write bandwidth usage for each running process on Linux. Iotop is very useful to troubleshoot disk performance…
Timeo is a timeout mount option in NFS mount. It is the timeout value that the NFS client uses to wait for a response before it retries an NFS request. Let’s dive into the details about what this timeout value…
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…
top is a powerful command for periodically displaying a sorted list of system processes. On Linux its default sort key is %CPU—but when you’re chasing a memory leak or a RAM-hungry process, you’ll want to sort by memory instead. Here are three…
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…
Ask a Linux server “how much memory is free?” and the honest answer is “it’s complicated.” Modern Linux deliberately uses almost all your RAM—for caches, buffers, and reclaimable structures—because unused memory is wasted memory. That’s why the number people fixate…
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…
The tar command bundles multiple files and directories into a single archive. It’s similar to zip, with one key difference: zip files are always compressed, while tar files can be compressed but don’t have to be. The most common form you’ll see—.tar.gz—is a tar archive compressed with gzip. Basic…
