Switch Port Analyzer (SPAN) ports have a well-documented ceiling. Under sustained load, they drop packets. They strip Layer 1 errors. They share switch CPU resources with production traffic. For teams trying to run Intrusion Detection Systems (IDS), Network Detection and Response (NDR) tools, or lawful intercept probes, that ceiling matters. A monitoring architecture built on SPAN ports isn't really monitoring – it's sampling.
The shift toward hardware Test Access Points (TAPs) is accelerating across enterprise, telecom, and industrial environments for exactly this reason. TAPs copy 100% of traffic passively, with no impact on the production link. When power fails, the link stays up. When traffic bursts, no packets are dropped.
This guide examines six verified network TAP vendors for teams making that transition. It covers verified product specifications, key differentiators, and practical guidance for selecting the right solution for your environment.
| Vendor | Key Strength | Max Speed |
|---|---|---|
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Hybrid TAP/packet broker, scale-out architecture |
Up to 400G |
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Purpose-built TAP portfolio with OT and data diode options |
Up to 100G |
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Highest port density, broadest TAP type range |
Up to 400G |
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Deep observability pipeline integration, Always On copper TAPs |
Up to 400G |
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Portable TAPs with hardware timestamping, 10-year fiber warranty |
Up to 10G |
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Carrier-grade density, MTP/MPO high-speed TAPs |
Up to 400G |
Network Critical delivers network TAPs and packet brokers as a unified modular platform – a design that directly addresses one of the most common pain points in SPAN port replacement: organizations often discover, after deploying TAPs, that they need intelligent traffic management to distribute traffic across multiple tools. Network Critical removes that second-phase cost by combining both functions in a single chassis.
The SmartNA-XL supports 1/10/40G and includes passive fiber, active copper, and bypass TAP modules in a 1RU chassis. It supports aggregation, filtering, load balancing, packet slicing, payload masking, and header stripping – features typically requiring a separate packet broker. The SmartNA-PortPlus scales from 48 to 194 ports across 1/10/25/40/100G, with a non-blocking 1.8Tbps backplane. For 400G environments, the SmartNA-PortPlus HyperCore provides 32 QSFP-DD interfaces and 25.6Tbps aggregate throughput.
All platforms are managed through Drag-n-Vu, Network Critical's patented graphical configuration interface. Filter creation and port mapping are handled through drag-and-drop interaction, with automated rule generation eliminating the risk of misconfiguration. A RESTful API enables direct machine-to-machine integration with security tools – demonstrated in a published integration with Darktrace, allowing the platform to dynamically adjust traffic filters without human intervention.
Passive fiber TAPs in the portfolio require no power and introduce no network latency. Fail-safe copper TAP modules maintain the network link even during complete power loss.
Proven results:
Garland Technology positions itself as a purpose-built TAP vendor, and its product range reflects that focus. The portfolio covers passive fiber TAPs in both multimode and single-mode variants, active copper TAPs with fail-safe circuitry, breakout TAPs, aggregation TAPs, inline bypass TAPs, and hardware data diode TAPs – a breadth that covers most deployment scenarios without requiring additional vendors.
Passive fiber TAPs are available in portable form factors and high-density 1U chassis accommodating 16 to 24 TAP modules. Network speeds supported range from 1G to 100G. Active copper TAPs include Garland's No Break fail-safe functionality, ensuring a very short link recovery time following power disruption rather than a full link renegotiation cycle.
For OT and high-security environments, Garland's hardware data diode TAPs enforce unidirectional traffic flow at the physical layer, preventing any data injection back onto the monitored network. This makes them well suited to Industrial Control System (ICS) environments requiring air-gap-equivalent monitoring. Garland also manufactures a military-grade industrial TAP rated for harsh environments, supporting 10/100/1000M copper links. All TAP products are manufactured and tested in the USA, with TAA compliance across the range.
Garland supports its products with an extensive library of technical documentation, including split ratio guides, installation notes, and OT-specific use cases.
Keysight Technologies brings test equipment heritage to its network TAP portfolio, with coverage from 1G to 400G across copper, multimode fiber, and single-mode fiber – and explicit support for specialized link types including Cisco BiDi. The company claims the largest range of TAP types of any vendor, and the Flex Tap VHD supports up to 36 TAPs in a single 19-inch 1U chassis, a density advantage meaningful in large-scale deployments where rack space is constrained.
The iLink Aggregator product line addresses a specific gap that SPAN port users often encounter during migration: the need to aggregate traffic from multiple existing SPAN ports or newly deployed TAPs before feeding monitoring tools. The iLink LA2-SPAN-T supports 16 copper input ports and four SFP+ monitor ports, allowing organizations to migrate incrementally – retaining SPAN sources while adding TAP-sourced traffic into a unified aggregation layer.
Tough Taps extend Keysight's TAP capabilities into industrial and ICS environments, with DIN rail mounting and certification for extreme operating temperatures. These are TAA compliant and independently certified. All Keysight TAPs carry no IP address and are isolated from the network, eliminating the management attack surface that managed SPAN configurations introduce. Keysight undertakes design-phase and manufacturing-phase testing on TAPs using the same equipment it sells for network test and measurement, a process that supports its zero packet loss performance claims.
Gigamon offers network TAPs as the access layer of its Deep Observability Pipeline, a platform designed to feed traffic to security, monitoring, and analytics tools across physical, virtual, and cloud environments. For teams replacing SPAN ports as part of a broader observability strategy – rather than a standalone TAP deployment – Gigamon's integrated approach is worth considering.
The G-TAP M Series provides passive fiber TAPs in half-RU and 1RU chassis configurations, with up to six TAP modules per 1RU chassis. Supported speeds reach 100G. These TAPs are unidirectional by design, with data flowing strictly from the network to monitoring tools. For copper links, the G-TAP A Series includes 10/100/1000Mbps and 1/10Gbps active TAPs with battery backup and fail-to-wire capabilities that eliminate link renegotiation during power transitions. SNMP traps alert operators to power state changes and link events.
Gigamon TAPs feed into the GigaVUE TA Series aggregation nodes, which support traffic from 1G to 400G and run GigaVUE-OS for packet broker functions including filtering, load balancing, and Flow Mapping. Management is centralized through the GigaVUE-FM single-pane-of-glass interface, which also covers cloud and virtual visibility. For organizations already using GigaVUE infrastructure, the TAP range integrates natively. Gigamon serves over 4,000 customers globally, including more than 80% of Fortune 100 enterprises.
Profitap serves two distinct use cases: permanent infrastructure TAPs for data centers and field-portable TAPs for network engineers who need to deploy capture capability rapidly at any point in the network. The ProfiShark series covers the portable use case, with the ProfiShark 1G and ProfiShark 10G providing bus-powered TAPs that connect via USB 3.0 and support capture to disk through the ProfiShark Manager application.
The ProfiShark 10G accepts 1G and 10G SFP cages for both fiber and copper links. Hardware timestamping is built in across the range at 5–8ns resolution, important for timing-sensitive forensic analysis and latency troubleshooting – contexts where SPAN port timestamp inaccuracy creates significant problems. Packet slicing is available on all ProfiShark models, processed in hardware on ingress with no CPU impact on the connected host.
For permanent installations, Profitap's fiber TAP range covers single-mode and multimode links with a 10-year warranty on passive components. Passive fiber TAPs have no IP address and introduce no active electronics into the link. Copper TAPs support 10M/100M/1G/10G with the No Break fail-safe mechanism. An optional secure TAP configuration includes tamper-evident seals and a physical data diode that prevents injection from monitor ports into the operational network. Profitap also offers a Cloud TAP product for Kubernetes and Azure VM environments, extending physical TAP visibility principles to virtual infrastructure.
Cubro Network Visibility is a European vendor with a strong carrier-grade product focus. Its OptoSlim TAP Series is designed for high-density, space-constrained deployments, available in 1RU and 3RU form factors with support for fiber speeds from 10Mbps to 400G. The 400G SR8 TAP supports high-speed parallel optics links common in hyperscale data center interconnects, a segment where SPAN port alternatives are either unavailable or impractical at scale.
Cubro TAPs support MTP/MPO connector types used in 40G and 100G parallel fiber environments, alongside standard LC and SC connectors. Converter TAPs handle media conversion for environments where link types need to be bridged before reaching monitoring tools. Copper TAPs support 10/100/1000 with USB interface options for certain configurations. Cubro was selected as a Vodafone supplier, validating its products in demanding carrier-scale environments. The company individually tests and certifies each unit before shipment.
Before selecting hardware, inventory your links. A site with mixed copper 1G access layer links and 10G/40G uplinks will need different TAP types – or a modular platform that accommodates both from a single chassis. Replacing SPAN ports link by link with the wrong TAP form factor leads to vendor proliferation and management complexity over time.
Some monitoring tools require separate TX and RX streams (breakout mode). Others need aggregated full-duplex traffic from a single input port. If you're feeding multiple tools from the same link, you need regeneration or replication capability – which not all standalone TAPs provide. Hybrid network packet brokers that combine TAP access with intelligent traffic distribution eliminate the need to deploy separate devices for each function.
SPAN port replacement is rarely a single-phase project. Start by identifying which links are highest priority – typically those feeding security tools or subject to compliance requirements – and select a TAP architecture that can grow incrementally without requiring infrastructure replacement. Key questions:
For SPAN port replacement on production links, fail-safe behavior is non-negotiable. Confirm whether a TAP maintains the network link during complete power loss, and the exact mechanism – relay-based fail-to-wire is standard for copper TAPs. For passive fiber TAPs, confirm there are no active components in the optical path that could disrupt the link.
Regulated environments in finance, healthcare, and government often have specific requirements for traffic capture fidelity. SPAN ports can drop packets and strip Layer 1 and select Layer 2 data, which may compromise compliance audit trails. Hardware TAPs capture 100% of traffic including malformed frames and errors. If your compliance framework – such as FISMA, NERC CIP, or HIPAA – requires complete packet capture, that requirement should drive TAP selection rather than cost or convenience.
If any of the links you're monitoring are in OT, ICS, or industrial environments, standard data center TAPs may not be appropriate. Industrial TAPs must operate across extended temperature ranges, support DIN rail mounting, and resist electromagnetic interference. Some deployments require data diode functionality to prevent any traffic from flowing back toward the monitored network. Verify ruggedization ratings before deploying into process control or manufacturing environments.
A SPAN port mirrors traffic in software on a switch, using switch CPU resources to copy packets to a designated monitor port. A network TAP is a dedicated hardware device that creates a physical copy of all traffic passing through a link. TAPs capture 100% of traffic including Layer 1 errors and malformed frames – data that SPAN ports discard. Under high load, SPAN ports drop packets to protect switch performance; TAPs do not. TAPs also maintain the network link during power failure, whereas SPAN port monitoring depends on switch availability.
Passive fiber TAPs introduce near-zero latency – typically less than a microsecond – because the optical split is a physical process with no active electronics. Active copper TAPs introduce a small amount of latency through their relay and electronic circuitry, but this is measured in nanoseconds and is not perceptible to production traffic. In latency-sensitive environments such as high-frequency trading or real-time industrial control, passive fiber TAPs are preferred for exactly this reason.
Yes. TAPs capture full-duplex traffic by design. Most TAPs output two separate monitor streams – one for each direction of the link – which can be delivered to a monitoring tool as separate inputs, or aggregated into a single stream using the TAP's built-in aggregation function or a downstream packet broker. This contrasts with SPAN configurations where combining ingress and egress on the same monitor port frequently results in duplicate packets.
A basic breakout TAP feeds two monitor ports – one per traffic direction. Regeneration TAPs replicate each monitor stream to multiple outputs, allowing one TAP to feed up to eight tools simultaneously on the same link without additional infrastructure. Where you need more sophisticated traffic distribution – filtering different traffic to different tools, or load-balancing across a tool cluster – a hybrid TAP solution combining TAP access with packet broker intelligence is the most efficient architecture.
Passive fiber TAPs require no power and are unaffected by power loss – the optical split is a passive physical process that continues regardless of external conditions. Active copper TAPs include fail-to-wire circuitry that connects the two network ports directly when power is lost, maintaining the link without disruption. Bypass TAPs used to protect inline security tools use the same fail-safe principle to keep traffic flowing if the protected appliance fails or is taken offline.
Passive TAPs and most active TAPs carry no IP address and have no management plane exposed to the network. They are completely invisible to network scanning, which means they cannot be discovered, fingerprinted, or targeted by attackers. This is a meaningful security advantage over SPAN-based monitoring, where the monitoring configuration is visible in switch management interfaces and can be identified or disabled by anyone with switch access.
Replacing SPAN ports is a decision that compounds over time. The operational cost of missed packets, incomplete forensic data, and failed compliance audits consistently exceeds the upfront cost of deploying hardware TAPs.
Network Critical's modular platform is designed for teams that need to start at a specific set of links and grow without infrastructure replacement. The SmartNA-XL and SmartNA-PortPlus combine TAP access and packet broker intelligence in a single chassis, eliminating the two-device architecture that most SPAN replacements evolve toward. Proven deployments at Vodafone, HSBC, and BP demonstrate the platform's capability in environments where 100% capture fidelity is non-negotiable.
To discuss your network's specific TAP requirements and get a free network audit, speak to the Network Critical team.