Exploring Netstat Command

Exploring Netstat Command

Examples and Usage in RHEL 7 and Ubuntu

Introduction

Netstat, short for network statistics, is a powerful command-line tool used for monitoring network connections and troubleshooting network-related issues in Linux systems. Whether you're managing a server on Red Hat Enterprise Linux (RHEL) 7 or Ubuntu, Netstat provides valuable insights into network activities. In this article, we'll delve into Netstat command examples and its usage in various scenarios.

1. Basic Netstat Command

The fundamental usage of Netstat is to display a list of active network connections. Open a terminal and type:

 netstat

 

This will provide a snapshot of all active connections, their status, and associated IP addresses and ports.

2. Displaying Listening Ports

To view the services and applications currently listening on specific ports, use the following command:

netstat -l
 

This will show a list of ports that are actively listening for incoming connections.

3. Displaying Network Statistics

Netstat can also provide detailed network statistics, including various protocols and their corresponding statistics. Execute the following command:

netstat -s
 

This will display a comprehensive overview of network statistics, helping you identify potential issues.

4. Displaying Process ID with Netstat

To identify which process is associated with a specific network connection, add the -p option to the command:

netstat -p
 

This will show the Process ID (PID) along with the network connections, aiding in troubleshooting and process management.

5. Displaying IPv4 and IPv6 Connections

Differentiate between IPv4 and IPv6 connections using the following command:

netstat -tuln
 

This command will display all listening UDP and TCP connections along with their corresponding IP versions.

6. Displaying Routing Table Information

Netstat can be used to show the kernel routing table:

netstat -r
 

This command provides insights into the system's routing configuration, helping you understand how data is directed through the network.

7. Monitoring Real-time Network Traffic

For real-time monitoring, the -c option refreshes Netstat output at regular intervals:

netstat -c
 

This is particularly useful for observing changes in network connections as they happen.

Conclusion

Netstat is an indispensable tool for network analysis and troubleshooting on Linux systems. Whether you're managing a Red Hat Enterprise Linux 7 server or an Ubuntu system, the Netstat command provides valuable insights into network activities, aiding administrators in maintaining a secure and efficient network environment. Experiment with these Netstat command examples to enhance your understanding and proficiency in Linux network management.

Remember, while Netstat is a powerful tool, it's always essential to complement it with other network monitoring tools to get a comprehensive view of your system's network health.