Table of content

July 3, 2024

What is Network Sniffing? Definition, Tools, and Protection

Networking sniffing is an excellent functionality for organizations to analyze traffic for trouble connectivity application performance or investigate increases in excessive bandwidth utilization.

Hackers are also huge fans of network and packet sniffers. The data collected within their target’s network also reveals IP addresses, communication ports, and a list of top talkers.

Organizations concerned about rogue network sniffing, packet analyzers, and digital eavesdropping should consult ForeNova, a managed detection and response (MDR) security provider. ForeNova’s MDR practice contains a network detection and response (NDR) monitoring capability to identify and block rogue sniffing activity within your organization’s network and cloud instances.

Are you interested in learning more about packet and network sniffing?

Schedule a demo today!

Understanding Network Sniffing

Placing a device on the network that plugs into a SPAN port of a layer2/layer3 switch can accomplish network sniffing in either passive sniffing or active mode. An application loaded on a virtual machine spanning several virtual network interfaces could also do sniffing.

Network engineers, security operations networks, and application security teams commonly use network sniffer tools. These tools collect all traffic across specific subnets or traffic sent to a SPAN port. Network sniffers are a valuable tool for detecting rogue devices, including Wi-Fi access points, printers, and Internet of Things (IoT) devices recently introduced into the network.

There are three standard sniffing techniques by hackers and internal networking teams:

MAC Spoofing

Hackers and internal teams wanting to collect MAC addresses across all segments will execute this form of sniffing. Internal teams will take this information and create access control lists (ACLs), allowing only these MAC addresses to resonate on the networks. Hackers love to gain access to their targets’ MAC addresses to establish a rogue presence by spoofing an approved MAC.

MAC Flooding

MAC flooding is a common hacker technique designed to overwhelm the local network segments by sending unique MAC addresses attempting to dominate the network infrastructure.

DNS Cache Poisoning/Evil Twin

Hackers will attack your organization’s DNS by altering the various records and redirecting network traffic. Hackers call this redirection an “evil twin.”

Standard Tools for Network Sniffing

Network and security teams have a wide variety of sniffing tools available. Cybersecurity solution manufacturers sell many of these tools. While others are available through the open-source community. Here is a short list of tools:


Wireshark is one of the most used sniffer tools. The tool helps capture valuable network telemetry information between sources and designations within the network. The hacker community also commonly uses this open source.

The tool has a very easy-to-use UI filled with pre-configured filtering to help engineers troubleshoot faster.


tcpdump is a computer program that analyzes data network packets and operates through a command-line interface. This tool allows the user to monitor TCP/IP and other packets being sent or received over the network to which the computer is connected. Tcpdump is free software available under the BSD license.


One of the largest providers of network performance tools, NetScout offers several tools to assist networking and security engineers in analyzing and benchmarking their local, wide area, cloud, and Wi-Fi networks.

How to Detect Network Sniffing?

Detecting network sniffing is challenging for most network and security teams. Organizations with substantial investments in NetScout, Wireshare, or tcpdump face even more significant challenges in discovering and blocking rogue sniffing technology.

The first key indicator would be excessive network traffic directed to a specific host. This sudden increase in network utilization could be the first step in detecting a new or rogue entity on the network.

Organizations concerned about this increase in traffic should invest in tools like Anti-Sniff, Sniff Detection, or Snort.

Preventing Network Sniffing

Network and security teams have several options to prevent rogue network sniffing. As more organizations extend their networks and applications into hybrid cloud and third-party hosted portals, detecting and preventing their traffic from being exposed and deploying these countermeasures must become a top priority.

Use Encryption

Organizations in the EU and other parts of the world already have an encryption presence. Healthcare information, personal information within the EU, or similar data within California require encryption. Ensuring all data is at rest and in transit, even within the internal network, stays encrypted helps prevent rogue sniffers from reading your data.

Implement Network Segmentation

Network segmentation continues to gain traction within organizations. It prevents ransomware attacks from spreading laterally within their target’s network. Attacks stop when they attempt to communicate with non-standard or unapproved ports.

This same network security capability also helps stop rogue sniffing behavior. Defining network segments allowing traffic sent from many ports into one can help. Preventing one-to-many copying is ideal for stopping a rogue sniffer from functioning. Network and security teams, through network segment policies, can designate only specific ports and hosts that can communicate in one-to-many capacities.

Regular Network Audits

Another valuable workstream organization should execute a regular network audit to validate only specific MAC addresses and IP addresses and communicate between the various segments. Hackers will attempt to alter their victim’s network, connect using a spoofed MAC or IP address, or try to load malware on an internal host. These security breach attempts should warrant an organization to hire third-party penetration testing to validate that the network security controls, including ACLs, firewalls, and intrusion detection systems, are functional, updated, and effective in stopping rogue sniffing activities.

Use Intrusion Detection Systems (IDS)

Intrusion detection systems (IDS) based on SNORT signatures became replaced with more advanced NDR powered by artificial intelligence (AI) and machine learning (ML). NDR capabilities live within the network to help spot changes in behavior, access, and bandwidth consumption. AI plays a critical role in preventing rogue sniffing. Hackers will rapidly alter their methods to embed their sniffer inside their target’s network and cloud segments. Using AI, hackers often deploy decoy sniffers within their target’s network, attempting to overwhelm the internal SecOps teams.

Organizations seeing an uptick in this attack vector should invest in a partnership with an MDR provider like ForeNova.

Recommended Methods for Securing a Network

Network security has transformed in the last several years. Network security has become more agile, adopting hybrid cloud infrastructure-as-a-service (IaaS) and platform-as-a-service (PaaS) offerings. Virtual network architectures, including network segmentation, virtual switching, and programmable networking, develop as more organizations move away from traditional static networks and towards deploying zero-trust, secure-access-secure-edge (SASE), and SD-WAN. These new network security strategies are up-and-coming in helping organizations protect themselves as they expand their security measures to include cloud services and support a mix of on-site and remote workers.

Cybersecurity breaches continue despite these new advanced networking architectures with embedded security protection layers. Email phishing attacks spread ransomware across their victims’ enterprises, Brute Force attacks against identity management systems, and the rise of insider threats continue to cause severe damage to organizations. Organizations reviewing their ability to support these next-generation network security architectures often realize they need more resources to manage these solutions.

Many of these next-generation networks have become more of a managed service. Managed security service providers (MSSP) and managed service providers (MSP) offer these services as a utility to help organizations save valuable capital resources and speed up their time-to-market solutions and services.

Building For Today, Managing for Tomorrow

Deploying next-generation network security requires experience and expertise. Architecting a security solution requires organizations to design, build, and optimize their security investment with the proper operations model.

ForeNova, a global MDR provider, understands the need for organizations to deploy next-generation network security. They purposefully designed their MDR solution to help small enterprises (SMEs) and larger organizations in the EU, which face considerable challenges from cyberattacks and constant changes in compliance regulations.

Suspect Rogue Network Sniffing On the Network?

ForeNova Security is a leading provider of cybersecurity services and MSSP/MSP offerings. MDR solutions help identify and block rogue sniffing from happening on your legacy and next-generation networks. Monitoring, detection, and response are at the heart of ForeNova’s award-winning service.

For organizations seeking a partner to augment their current security operations (SecOps) team or provide complete 24/7 monitoring and response, threat intelligence, and other cyber defense tools, ForeNova Security has access to experienced engineers to meet their business and compliance goals.

Contact us today to discuss your needs for managed services.


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