Sniffing: A Beginners Guide In 4 Important Points

Ajay Ohri


Data packets are used to send and receive traffic online. The data packets carry lots of data and are often targeted by people who are looking for sensitive information. Today, some special tools and protocols can be used to access data from these packets making it crucial for cyber specialists to come up with strategies that can stop hackers from retrieving data from both public and private networks. This is known as sniffing. And, there are many tools for sniffing data, even from the world’s most secure networks. 

In this article let us look at:

  1. What is Sniffing?
  2. Types of Sniffing Attack
  3. Detection of Sniffing Attack
  4. Prevention of Sniffing Attack

1. What is Sniffing?

As mentioned previously, sniffing attacks focus on stealing customer information. These attacks are executed behind safe and secure channels. The attacks involve constantly monitoring and capturing the data transferred via packets in the network. Special packet sniffers are used for interfering with the data transfer and extract information. 

Many a time, people confuse data sniffing with spoofing. There are prominent differences between each of these network attacks. To begin with, sniffing is where the attacker actively gets involved in the conversation. They listen to the actual flow of data packets. As a result, they will be able to sniff segments that can make a big difference. This involves segments that carry passwords, sensitive information, personal data, and even credit card credentials.

On the other hand, spoofing is also known as a man in the middle attack. These are attacks where the hacker becomes an imposter. They find a way of positioning themselves between the machine (or network) and the target. As a result, any data transferred by the target has to go through the man in the middle. The tools and strategies used to host a spoofing attack are much different than the sniffing attacks. 

2. Types of Sniffing Attack

There are two major types of sniffing attacks. The passive and active sniffing attacks are equally common. To understand how to detect packet sniffing, it is important to learn more about the different types of sniffing attacks. 

Active sniffing attacks happen in switched networks. By definition, the switch is an important device that connects the host and the network. The Media Address Control is used by the switch to connect the devices. The MAC address is essential for forwarding traffic to the right devices connected to the switch. This behavior is utilized by the attackers. They find a way to inject traffic deep into the LAN layer. Consequently, this allows them to actively sniff content from the connection. 

Next, the passive sniffing attacks replace the switches with hubs. The MAC address is used by the hubs. However, the MAC address is only used to decide the destination ports of the data transfer. Passive attacks are much simpler and faster than active attacks. Why? The hacker only has to find a way into the LAN network. Once they find a way of getting connected in the data transfer network channel, they will be able to sniff. 

Regardless of the sniffing methodology, this kind of attack plays an important role in extracting crucial pieces of information from the network. 

3. Detection of Sniffing Attack

The method used for detection strongly depends on the complexity of the attack. In many cases, the attack can go unnoticed. There are anti sniffer solutions that may even identify a sniffer attack. However, these attacks are known to be false positive. This is why cyber specialists follow protocols to judge if an attack is real or not. Also, you need to figure out what is a sniffer tool meant to do in your workflow. This way, you will be able to master how a sniffer works, and how it would blend with your existing (or proposed) security strategies. 

Wireshark is a widely used tool for identifying sniffing attacks. This is an open-source platform that takes care of analyzing and capturing network traffic. The tool runs on Linux and Windows machines. The packets transferred over the network can be tracked easily using the Wireshark tool. Moreover, it helps in filtering the packets based on protocol, IP, and a few other parameters. 

Debookee is a paid tool for analyzing and monitoring the network. This tool is capable of intercepting traffic from multiple devices. The methods used by this tool are completely independent of the devices used. This means traffic from phones, laptops, and even tablets can be monitored using the tool. The SSL/TLS decryption strategy used by the Debookee is known for supporting secured layer communication. 

Another impressive tool for capturing sniffing attacks would be dSniff. This tool became famous for spotting password sniffing in networks. 

4. Prevention of Sniffing Attack

To begin with, users should be cautious about the network they use to transfer data. The kind of data used and shared across free public wireless networks has to be controlled. This is because the chances of a hacker sniffing in these public platforms are extremely high. It is quite easy for hackers to build fake wireless networks. These networks lure traditional users into establishing a connection and transferring data. This is why users need to think twice before access free public WiFi services.

Encryption is a formal solution to sniffing attacks. This ensures that every piece of information transferred over the network is carefully encrypted. The receiving end needs to have the right decryption methods for understanding the actual message. Encryption to avoid sniffing attacks can be achieved easily in a virtual private network (VPN). 

Network monitoring and analyzing are two important stages in identifying and preventing network attacks, of all sizes and types. Periodic monitoring and carefully drafted plans can help you judge the presence of a sniffing attack. However, the checks have to be performed periodically. Else, the chances of your missing an attack are extremely high. 

Many times, ethical hackers make use of the methods used by hackers to penetrate systems to identify prevention strategies. These steps turn into effective contingency plans. 


On the whole, network sniffing attacks are prone to occur at any time. Users need to be extremely cautious about the way they use and connect with networks. At all times, data needs to be transferred via a safe and encrypted channel. This reduces the risks of a sniffing attack. Also, organizations need to safeguard their virtual private networks to ensure that hackers cannot eavesdrop on any communication that happens.

So, have you made up your mind to make a career in Cyber Security? Visit our Master Certificate in Cyber Security (Red Team) for further help. It is the first program in offensive technologies in India and allows learners to practice in a real-time simulated ecosystem, that will give you an edge in this competitive world.

Also, Read

Sniffing and Spoofing: Important Points to know in 2021

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