How to use Linux for network traffic analysis

In the field of network security, network traffic analysis is a very important task. By analyzing the data traffic in the network, abnormal behaviors and suspected attack behaviors in the network can be discovered, so that timely measures can be taken to prevent attacks from continuing to occur. As a free and open source operating system, Linux system has very powerful network traffic analysis tools. This article will introduce how to use Linux for network traffic analysis.

1. Install packet capture tools

In Linux systems, the most commonly used packet capture tools are tcpdump and wireshark. They are all open source software and can be downloaded and used for free. In the Ubuntu system, you can install it through the following commands:

sudo apt-get install tcpdump wireshark

After the installation is completed, you can start using it.

2. Packet Capture Operation

1. Use tcpdump to capture packets

When using tcpdump to capture packets, you can add filtering rules as needed and only capture packets that match the rules. . Commonly used filtering rules include:

a. Filter by protocol, such as capturing only TCP protocol packets

sudo tcpdump tcp

b. By source IP and destination IP Filter, for example, only capture the data packets with the source IP of 192.168.1.1

sudo tcpdump src 192.168.1.1

c. Filter by port number, for example, only capture the data with the destination port of 80 Package

sudo tcpdump dst port 80

2. Use wireshark to capture the packet

When using wireshark to capture the packet, you can view the detailed information of the data packet more intuitively. After opening wireshark, select the network card to be captured and click the "Start capture" button to start capturing packets. After the packet capture is completed, you can filter it through Wireshark's filtering function. Commonly used filtering rules are similar to tcpdump.

3. Traffic analysis

1. Use tcpdump for traffic analysis

The data captured using the tcpdump tool is output in hexadecimal format. You can use the "-A" parameter to output in ASCII code form, which is more convenient for analysis. At the same time, you can also use the "-n" parameter to prohibit domain name resolution.

sudo tcpdump -A -n

2. Use wireshark for traffic analysis

Open the captured packet file and you can view detailed traffic information directly in wireshark . Can perform protocol parsing, filtering and statistical analysis on traffic. For example, you can find all HTTP requests, or find all packets whose source IP and destination IP are a certain IP, etc.

4. Data Visualization

In addition to using command line tools for traffic analysis, you can also use certain data visualization tools to present the analysis results in a graphical interface. These tools can display the analyzed data in charts or visualizations. For example, you can use the Kibana tool to visualize data.

Summary

This article introduces how to use Linux for network traffic analysis. Through packet capture tools such as tcpdump and wireshark, data packets in the network can be captured and analyzed in detail. At the same time, through data visualization tools, the analysis results can also be displayed in charts or visualizations. Network traffic analysis is a very important link in ensuring network security. I hope this article can provide you with some help.

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