How to Identify IP Addresses Sending Many Requests in Ubuntu Linux


In today’s interconnected world, network security is paramount. One aspect of network security involves identifying and monitoring IP addresses that may be sending an unusually high volume of requests to your system. In Ubuntu Linux, several tools can help you accomplish this task effectively.

Using netstat

One of the simplest ways to identify IP addresses sending many requests is by using the `netstat` command. Open a terminal and enter the following command:

sudo netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr

This command will display a list of IP addresses that have initiated numerous TCP connections to your system, sorted by the number of connections.

Utilizing tcpdump

Another powerful tool for network analysis is `tcpdump`. In the terminal, execute the following command:

sudo tcpdump -nn -c 1000 | awk '{print $3}' | cut -d. -f1-4 | sort | uniq -c | sort -nr

This command will capture the last 1000 packets and display a list of IP addresses involved in those packets, sorted by packet count.

Monitoring with iftop

If you prefer a real-time view of network traffic, `iftop` is an excellent option. If you haven’t installed it yet, you can do so with the following command:

sudo apt install iftop

Once installed, simply run `iftop` in the terminal:

sudo iftop

`iftop` will display a live list of IP addresses sending and receiving the most traffic on your system.

By utilizing these tools, you can effectively identify IP addresses that may be engaging in suspicious or excessive network activity on your Ubuntu Linux system. Monitoring and promptly addressing such activity can help enhance the security and performance of your network environment.

Stay vigilant and keep your systems secure!