7.3.5

Npcap is a packet capture and injection driver for Windows systems designed to provide low-level access to network traffic for analysis, monitoring and security tooling.
Npcap operates in kernel mode using NDIS, enabling efficient packet processing and support for loopback traffic capture, raw 802.11 frames, and promiscuous mode on compatible adapters.
It exposes a WinPcap-compatible API, allowing legacy applications to function while enabling new implementations through libpcap-based bindings and custom filter expressions compiled into BPF bytecode.
Npcap supports packet filtering using Berkeley Packet Filter syntax and integrates with modern Windows filtering stack for improved stability compared to legacy capture drivers.
It provides loopback capture capability for localhost traffic analysis, enabling debugging of inter-process communication and service-level network interactions without external interfaces.
Deployment typically involves installing the driver with administrative privileges and ensuring compatibility with existing network stack configurations and virtualization environments.
Typical use cases include intrusion detection systems, protocol analyzers, traffic replay tools and performance monitoring agents operating at packet level.
Applications built on Npcap should handle high-throughput scenarios by implementing asynchronous capture loops and efficient memory buffering strategies.
Error handling must account for dropped packets, adapter changes and permission restrictions imposed by the operating system security model.
Proper configuration ensures deterministic capture behavior in production environments.
Integration with security monitoring pipelines requires careful tuning of capture rates, buffer sizes and filtering rules to maintain accuracy under load conditions in production systems.