pktgen

Pktgen is a packet generator used to produce synthetic network traffic for benchmarking and testing. It can generate deterministic or random patterns, measure throughput and latency, and help validate network devices, drivers, and configurations. It is commonly used to test NICs, switches, virtual networks, and transport stacks.

In Linux, pktgen is a kernel module in the net/pktgen subsystem. It exposes a set of virtual transmit ports configured via the procfs interface under /proc/net/pktgen. Users configure packet size, rate, burst, and header templates (Ethernet, IPv4/IPv6, TCP/UDP). Ports can be coordinated across CPUs to generate multi-threaded traffic. It runs with elevated privileges and is used in labs and continuous integration environments.

DPDK pktgen refers to a user-space traffic generator provided by the DPDK project. This implementation uses DPDK drivers to generate traffic at high rates, bypassing the kernel network stack. It supports many ports, flexible packet formats, and advanced traffic patterns, and is used for high-speed NIC benchmarking on systems with large pages.

Typical use cases include measuring throughput and latency, stress testing under bursty traffic, and validating queueing and scheduling behavior. Limitations differ by implementation: the kernel(pktgen) variant incurs kernel overhead and may be limited at extreme rates, while the DPDK version requires specialized environments (such as hugepages) to achieve hardware line rates.