Do You Really Need Failsafe Network TAPs?

by John He October 01, 2025

Network TAPs are critical tools in network monitoring, providing a passive method to capture and analyze network traffic without disrupting data flow. One feature often highlighted in network TAP specifications is the failsafe or failover feature, which ensures that the Ethernet link remains operational during a power outage. However, in high-availability (HA) network setups, where backup links are typically employed to handle scenarios like power outages, the necessity of this failsafe feature becomes questionable. This article explores the role of network TAP failsafe features, their relevance in HA environments, and why they may not always be essential.

What Is a Failsafe Network TAP?

A failsafe network TAP is designed with mechanical relays or optical bypass circuits that automatically close when the device loses power. This allows traffic between two connected devices (for example, switches or firewalls) to keep flowing even when the network TAP itself is offline. Without such a mechanism, a TAP failure could cause the link to drop.

This feature is often marketed as a critical advantage, particularly in environments where network uptime is paramount. However, the real-world necessity of this feature depends heavily on the network architecture, particularly in setups designed for high availability.

High Availability and the Active + Standby Model

Modern HA network design already addresses this type of risk by employing redundant physical links. A common method is the active + standby (or active + backup) model, in which:

Multiple links are provisioned between devices.
One link is designated as active, carrying all production traffic.
Additional links remain in standby mode, ready to take over if the active link fails.
If the active link goes down (whether due to cable damage, port failure, or a network TAP losing power), a standby link is automatically activated.

Protocols such as Link Aggregation Control Protocol (LACP) can be configured to run in active/standby mode, or switching protocols like Rapid Spanning Tree (RSTP) can achieve similar behavior. In either case, the network continues operating without interruption.

This architecture ensures that a single point of failure, including the loss of a link passing through a network TAP, does not disrupt service.

Network TAPs in HA Environments

When a network TAP is deployed in an HA environment, it is typically inserted into one of the active links. If the TAP loses power and lacks a failsafe feature, the Ethernet link could fail, disrupting traffic on that path. However, in an HA setup with redundant links, the network is designed to handle such failures. The redundant link would take over, and traffic would continue to flow, albeit through the backup path.

For example, consider a scenario where two switches are connected via two links: a primary link with a network TAP and a secondary link without one. If the tap loses power and lacks a failsafe feature, the primary link goes down. The network’s HA mechanisms (e.g., STP or LACP) detect the failure and reroute traffic through the secondary link. While there may be a brief disruption during the failover (typically milliseconds to seconds, depending on the protocol), the network remains operational.

As can be seen, in mission-critical networks with built-in redundancy or high-availability, the incremental value of failsafe network TAPs is often limited; in some cases, deploying non-failsafe TAPs can be the better choice, reducing complexity and costs while enhancing overall reliability:

Built-in Resilience: Backup links already guarantee continuity when one link fails.
Simplicity and Reliability: Non-failsafe network TAPs avoid added complexity and moving parts, which can improve reliability and reduce costs.
Operational Transparency: If a link drops, monitoring systems detect it and alert engineers. A failsafe tap may keep the link up but hide the underlying issue, delaying corrective action.
Strategic Focus: Investment in robust redundancy provides greater long-term resilience than relying on bypass features inside monitoring devices.

When Failsafe Helps and Why It May Not Be Necessary

Failsafe network TAPs may provide value in certain environments:

Single-link setups: If only one link exists and a network TAP loses power, the failsafe mechanism keeps traffic flowing.
Legacy deployments: Where network redesign is not feasible, failsafe feature of a network TAP can offer an added safeguard.

However, it is important to note that a single-link, non-redundant environment usually signals that the connection is not mission-critical. If uninterrupted service were truly required, redundancy would be the correct architectural solution. In such cases, relying on a failsafe feature of the network TAP may address the symptom but not the underlying design limitation.

Conclusion

Failsafe network TAPs are often promoted as critical for traffic continuity, but their true value depends on deployment context. In well-architected high-availability networks, redundancy mechanisms such as active + standby links already guarantee uninterrupted traffic flow. In these cases, the failsafe capability of network TAPs is not only unnecessary but can sometimes be counterproductive.

Where redundancy is absent, failsafe TAPs can provide some protection, but the very lack of redundancy usually signals that the link is not business-critical. In such cases, a failsafe network TAP may not justify the additional investment.

Ultimately, the choice of network TAPs should align with overall infrastructure strategy: build redundancy where uptime matters most, and deploy simpler network TAP solutions where visibility is needed without unnecessary complexity.

Dualcomm provides a range of non-failsafe network TAPs supporting both copper and optical fiber links, with speeds from 100 Mbps up to 10/25 Gbps, offering a cost-effective solution for mission-critical networks with built-in redundancy or high availability. Contact Dualcomm for expert guidance on the right network TAP for your deployment.