Build the topology.
Watch the packets.
Prove the reach.
A deterministic, in-browser simulator. Type real CLI on a multi-vendor IR, capture every frame, and prove reachability symbolically. No install, no licensed images, no telemetry.
Real gear is expensive. Other simulators are not honest.
Image-based emulators need licensed binaries and burn CPU per node. Toy simulators skip protocol depth. netverdict models behaviour directly and deterministically.
What you get
Real CLI
Type familiar commands and see parser errors inline.
Packet visibility
Capture ARP, OSPF, BGP, MPLS and service traffic as reproducible traces.
Symbolic reachability
Inspect all matching flows, drop reasons, and per-hop decisions.
Multi-vendor IR
Different CLI styles feed the same canonical model.
What is verifiable
Every result is deterministic: packet path, route state, and verdict are replayable. That makes troubleshooting feel like engineering work instead of guesswork.
Open the workspace.
Free in your browser, shareable by URL, and built for repeatable engineering work.