No. 3 of 31 ·Network Testing Software

TRex

Web · Windows · Mac · Linux · Self-hosted · API

Freedom report

Three barsScore 6.7

Free tierA free tier is on its own pricing page
Open codeNo open-source code on record
Runs widely4 of 6 device platforms
DocumentedPlans, terms and facts published

TRex is ranked #3 of 31 in network testing software on Freedom251. It runs on API, Linux, macOS, Self-hosted, Web, Windows. There is a free plan.

TRex plans and pricing

All plans

TRex Free Open source · Linux application · hardware and NIC requirements apply trex-tgn.cisco.com · 4 Oct 2026

Compared on network testing software

Free plan: Yes
Deployment: self_hosted
Test methods: both
Protocol support: TCP, UDP, ARP, ICMP, IPv6/ND, DHCPv4/v6, IGMP, DNS, DOT1X, LLDP, mDNS, NetFlow/IPFIX, OSPF, RIP, and GTP-U
API access: Yes

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The record

Purpose: TRex is an open source traffic generator for benchmarking platforms with realistic traffic.
Traffic generation: TRex generates L3–7 traffic and offers stateful and stateless traffic generation modes.
Stateless features: Stateless mode supports multiple streams, packet field changes, and per-stream or per-group statistics, latency, and jitter.
Stateful features: Advanced Stateful mode supports L7 traffic with scalable TCP and UDP.
Emulation protocols: Emulation includes ARP, IPv6, ND, MLD, IGMP, ICMP, DOT1X, DHCPv4, DHCPv6, and DNS.
Automation API: The documentation provides Python automation APIs for stateless, stateful, advanced stateful, emulation, and NDR functions.
Use cases: The FAQ lists high-scale stateful network-device benchmarks, DDoS traffic generation, switch testing, client and server scale tests, production tests, and routing protocol tests as use cases.
Operating system: The manual describes TRex as a Linux application that uses DPDK and interacts with Linux kernel modules.
Platform limit: The manual says TRex should work on COTS x86 servers; ARM compilation is possible but is not tested in its regression.
Support: The documentation lists a TRex community forum and Cisco DevNet community as support resources.
Security: The opened official pages do not state security certifications or compliance claims.
Traffic modes: It supports stateless, stateful, and advanced stateful traffic generation.
Advanced stateful: Advanced stateful mode emulates Layer 7 traffic over scalable TCP and UDP flows.
Protocol emulation: Its emulation functionality includes ARP, IPv6, ND, MLD, IGMP, ICMP, DOT1X, DHCPv4, DHCPv6, and DNS.
Price from: Free

Where it ranks on Freedom251

Best Network Testing Software in 2026#3 of 31

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Sources

trex-tgn.cisco.com· checked 3 Oct 2026
trex-tgn.cisco.com/trex/doc/index.html· checked 3 Oct 2026
trex-tgn.cisco.com/trex/doc/trex_faq.html· checked 3 Oct 2026
trex-tgn.cisco.com/trex/doc/trex_manual.html· checked 3 Oct 2026
trex-tgn.cisco.com/trex/doc/cp_stl_docs/api/client_code.ht· checked 4 Oct 2026
trex-tgn.cisco.com/trex/doc/cp_stl_docs/api/bird_node.html· checked 4 Oct 2026
trex-tgn.cisco.com/trex/doc/trex_vm_manual.html· checked 4 Oct 2026