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What is IP Sniffing?


Cybercriminals are always looking for new strategies to hack corporate employee credentials and IP sniffing has become a popular method for stealing sensitive data. This article will discuss what IP sniffing is, how it works and how to protect your organization from this type of attack.

So, what is IP sniffing?

IP sniffing is a technique used to intercept, monitor and log traffic over a TCP/IP network. The traffic is captured in packets, which are small chunks of data that are sent between devices on a network. IP sniffing can be used to track the activities of users on a network or to steal information from communications. Using this technique, cybercriminals 'sniff' for unencrypted information such as credentials, passwords, or confidential data over an unsecured network.

However, the technique has advantages as well. Network administrators and monitoring teams can use it to monitor and validate network traffic.

IP sniffing is divided into two categories:

  1. Active sniffing: In active sniffing, the attacker injects address resolution protocols (ARPs) into a network to redirect traffic to the attacker's machine

  2. Passive sniffing: Passive sniffing involves monitoring traffic that is already passing through a network device such as a switch or router. The attacker does not need to send any special packets or exploit any vulnerabilities

What are packet sniffers?

Any hardware or software monitoring network traffic is a packet sniffer. The name comes from their dedicated purpose to explore or 'sniff' streams of data packets flowing between the sender and the receiver. Sniffer tools can be largely configured in two ways:

  1. Filtered: In this configuration, the sniffer tool captures packets that contain explicitly mentioned data elements

  2. Unfiltered: Here, the sniffer tool will capture all possible packets and put them in the local hard drive for evaluation

Some popular IP sniffing tools are:

  • Wireshark

  • Paessler PRTG Network Monitor

  • NETRESEC NetworkMiner

  • ManageEngine NetFlow Analyzer

  • WinDump

  • Savvius Omnipeek

  • TCPdump

  • Telerik Fiddler

  • SolarWinds Network Performance Monitor 

Is IP sniffing legal?

Yes, IP sniffing is legal from a security standpoint. Security analysts rely on packet sniffing to determine whether a system has strong encryption to protect an application from unwanted data exposure. Capturing content within an organization as a part of monitoring is legal. But attackers use sniffing tools to illegally extract unencrypted user credentials like passwords, phone numbers, credit card details, etc.

Benefits of packet sniffing

Packet sniffing, also known as IP sniffing, helps zero in on new resources when the organization wants to scale its network capacity. It can also increase packet transferring efficiencies and troubleshooting. In addition, packet sniffing can also help:

  1. Analyze traffic by type and filter specific IP packets

  2. Network administrators in detecting the root cause of a network issue

  3. Allows monitoring of inbound & outbound network traffic

  4. Improve network security

  5. Allows the IT team to perform traffic analysis and bandwidth management

How to avoid IP sniffing attacks?

There are several preventive measures users can employ to ward off IP sniffing attacks.

  • Refrain from using unsecured networks (HTTP without SSL) to perform credit card transactions or login into any application

  • Use VPN to create an encrypted tunnel for communication

  • Avoid unreliable public Wi-Fi

  • Avoid clicking suspicious links

  • To learn more about preventative measures, contact security firms like Packetlabs.


As IP sniffing continues to gain popularity as a method of stealing sensitive data, organizations should take precautions and implement strategies to help protect themselves.

Contact the Packletlabs team today for a free, no-obligation consultation.