[English] Debian Almquist Shell (dash) netstat Usage: Display network connections and statistics

Overview

The netstat command is a powerful networking tool that displays network connections, routing tables, interface statistics, and more. It helps users monitor network activity and troubleshoot network issues.

Usage

The basic syntax of the netstat command is as follows:

netstat [options] [arguments]

Common Options

Here are some common options you can use with netstat:

• -a: Show all active connections and listening ports.
• -t: Display TCP connections.
• -u: Display UDP connections.
• -n: Show numerical addresses instead of resolving hostnames.
• -l: Show only listening sockets.
• -p: Show the PID and name of the program to which each socket belongs.

Common Examples

1. Display all active connections:

   netstat -a
   

2. Show only TCP connections:

   netstat -t
   

3. Display listening ports:

   netstat -l
   

4. Show numerical addresses:

   netstat -n
   

5. Display UDP connections with program names:

   netstat -up
   

Tips

• Combine options for more detailed output. For example, netstat -tunlp will show TCP and UDP connections along with the program names.
• Use grep to filter results. For instance, netstat -a | grep LISTEN will show only listening connections.
• Regularly check your network connections to identify any unauthorized access or unusual activity.