Linux iptables: Port Redirection Example

Port redirection (also known as port forwarding) is a useful technique for redirecting traffic from one port to another on a Linux system using the iptables firewall. Here’s an example of how to set up port redirection using iptables. Let’s say you have a web server running on port 8080, but you want to make … Read more

HowTo: Check RAM Size In Ubuntu Linux

To check the amount of RAM installed on your Ubuntu Linux system, you can use the free command. Here’s how: Open a terminal window by pressing Ctrl+Alt+T on your keyboard. Type the following command and press Enter: free -h The -h option will display the output in a human-readable format, making it easier to read. … Read more

Shutdown Linux Server Command

To shut down a Linux server, you can use the shutdown command. This command sends a message to all logged-in users, gives them a grace period to save their work, and then shuts down the system. To shut down the system immediately, you can use the following command as the root user: # shutdown -h … Read more

Debian / Ubuntu Record Boot Messages

By default, Debian and Ubuntu record boot messages to the system log. The system log is stored in the file /var/log/syslog and contains messages from the kernel and other system services. To view the boot messages in Debian or Ubuntu, you can open a terminal window and type the following command: $ dmesg This will … Read more

Unix / Linux: Save Output To File

In Unix/Linux, you can easily save the output of a command or script to a file using the “>” or “>>” operator. The “>” operator redirects the standard output of a command to a file, overwriting the file if it already exists. The “>>” operator appends the output to the end of the file, creating … Read more