When it comes to defending your IT network from cyber threats, the more invisible your solutions, the better. Network TAPs—test access points—are some of the most discreet yet simple solutions in modern cybersecurity.
Rob Joyce, retired Director of Cybersecurity at the National Security Agency (NSA), pinpointed their value when he remarked, “[An attacker’s] worst nightmare is that out-of-band network tap that really is capturing all the data, understanding anomalous behavior that’s going on, and someone is paying attention to it. You’ve gotta know your network, understand your network, because [the attacker] is going to.”
This blog will discuss the role of Network TAPs, explore their attributes, and share why they’re invaluable for network engineers and cybersecurity architects who want to stay a step ahead of potential attackers.
The Role of Network TAPs in Cybersecurity
Network TAPs are essential for any organization’s cybersecurity and network monitoring strategy, offering real-time access to data flowing across critical infrastructure. They work as passive devices, replicating network traffic without disrupting it.
A network TAP is a purpose-built device that sits between two network points and sends network data to external appliances without interrupting traffic flows. A passive TAP simply makes a copy of the network data and distributes it to third party tool(s).
Passive TAPs, as Garland defines them, are TAPs that will not cause the monitored devices to disconnect from the link between one another if power is lost. This can be accomplished when monitoring two devices connected with fiber optics or with two devices running 10 or 100 Mbps copper interfaces.
Why Network TAPs Are "Invisible"
No MAC Address
One critical feature of Network TAPs is that they don’t have a hardware MAC (Media Access Control) address. Most other network devices, whether routers, switches, or servers, require a MAC address to facilitate data link layer communications. While that makes these devices part of the network’s communication fabric, it also leaves a footprint cybercriminals could exploit.
Since Network TAPs skip the MAC address entirely, they remain undetectable—a perfect complement to cybersecurity monitoring.
No IP Address
Similarly, Network TAPs don’t use an IP address. IP addresses are crucial for identifying devices on a network, enabling them to communicate, but they are also a beacon for attackers. Hackers use IP addresses as entry points to scan networks for vulnerabilities or gain access to sensitive data.
The absence of an IP address in TAPs ensures complete invisibility from the eyes of cyber attackers, making them a core tool in thwarting network-based attacks.
Invisible to Hackers
For attackers, the ideal scenario is a network with no monitoring—or better still, monitoring devices they can target and disable. Network TAPs deny them this opportunity. Devoid of IP or MAC addresses, TAPs do not participate in your network’s communication operations. They lie entirely out of sight of scanning tools and malicious actors, quietly capturing and mirroring traffic.
This invisibility makes Network TAPs a cybersecurity architect's secret weapon. When deployed strategically, TAPs ensure clear visibility into dataflows while giving the attacker no notice. 
The Benefits of Network TAPs in IT Environments
The advantages of using TAPs in your network extend far beyond their stealthy nature. Let's explore some key benefits:
Enhanced Security Monitoring
TAPs provide a high-fidelity, full-duplex data stream to your monitoring tools, enabling comprehensive packet-level analysis. Unlike SPAN ports, which can drop traffic under heavy loads, TAPs supply an unaltered copy of all network traffic—no compromises. This ensures you’ll catch anomalies, performance issues, and potential vulnerabilities in real time.
Reduction of Blind Spots
Modern networks are complex and distributed, resulting in inevitable blind spots. TAPs remove these gaps, providing continuous visibility into network traffic—whether on-premises, in the cloud, or at hybrid environments. This level of insight is essential for understanding traffic patterns, compliance auditing, and threat detection.
Improved Diagnostic Capabilities
TAPs boost troubleshooting and diagnostics efficiency. If a performance issue arises or a breach occurs, the traffic captured by TAPs allows technical teams to reconstruct incidents with granular details, accelerating resolution times.
Scalability for Growing Networks
The modular nature of TAPs means businesses can expand their use in parallel with network growth. They integrate seamlessly into existing infrastructure without requiring significant reconfiguration, making them a future-proof solution for organizations scaling operations.
Reduced Latency for Monitoring
Unlike inline devices or SPAN ports, Network TAPs operate passively without delaying traffic—that’s critical for organizations with latency-sensitive operations, such as financial services, healthcare, or content delivery.
Real-World Impacts of TAP Deployment
The absence of Network TAPs in certain networks has, unfortunately, led to disastrous security breaches. Many cyberattacks could have been mitigated or entirely averted had TAPs been in place to help monitor suspicious traffic.
The United States National Security Agency (NSA), the U.S. Federal Bureau of Investigation (FBI), the U.S. Cybersecurity and Infrastructure Security Agency (CISA), the Japan National Police Agency (NPA), and the Japan National Center of Incident Readiness and Strategy for Cybersecurity (NISC) released a joint cybersecurity advisory recently that explained the activity of a China-linked cyber actor known as BlackTech. “BlackTech has demonstrated capabilities in modifying router firmware without detection and exploiting routers’ domain-trust relationships for pivoting from international subsidiaries to headquarters in Japan and the U.S. — the primary targets.” Authors cite BlackTech’s targeting and exploitation of various brands and versions of routers in this advisory. BlackTech was able to compromise routers and create backdoor access that remained undetected.
Placing a Network TAP between a router and firewall, the TAP copies of all traffic flowing between these two network devices and sends the copies to an out-of-band monitoring or security tool. Had the TAP been in place before a BlackTech breach, network teams may have spotted anomalies and detected intrusions early on, preventing further damage.
How to Add TAPs to Your Network
Deploying Network TAPs can seem daunting if unfamiliar with them. Here are five actionable steps to get started:
1. Network MappingIdentify points in your network architecture where visibility is essential – critical assets that allow the network to function, locations or network segments that pose the greatest risk, and the network edge.
2. Select the Right TAPChoose TAPs based on what you want to do with the copies of traffic (send to one or more security or monitoring tools) and your network specifications (speed, media type, and deployment requirements).
3. Seamless Installation
TAPs install with minimal disruption to operations. Also, TAPs are quick and easy to configure, requiring no additional follow-up once installed.
4. Integrate with ToolsetsConnect TAPs to your preferred security, monitoring, or analysis tools like Intrusion Detection Systems (IDS), Data Loss Prevention (DLP) solutions, or SIEMs.
5. Sit Back and RelaxEnjoy peace of mind that your security and monitoring tools will perform as promised because they are receiving the packet level data they need to protect and optimize the network.
By following these steps, you can ensure that your cybersecurity ecosystem benefits from the robust visibility that only TAPs provide.
Guaranteed Security for Modern Networks
Network TAPs are invisible but indispensable for cybersecurity architects and network engineers who demand reliable visibility into their infrastructures. Their lack of MAC and IP addresses allows them to stand watch silently, unnoticed by attackers, copying invaluable data to secure your enterprise.
The advantages of TAPs are numerous—they enhance security, improve diagnostics, and provide scalability as networks evolve. Through improved visibility and unwavering reliability, TAPs empower organizations to fend off threats and maintain operational confidence.
To elevate your network monitoring and cybersecurity efforts, incorporating Network TAPs is no longer optional—it’s the industry best practice.
Talk Further About Why Network TAPs are Invisible to Cyber Threats
Discover how Network TAPs boost cybersecurity through their invisibility. We are here to help you understand TAPs’ benefits, features, and why they're vital for monitoring modern networks. Join us for a brief network design consultation or demo. There's no obligation - it’s what we love to do! 