Simulate the network.Verdict in your browser.
NetVerdict is a deterministic network simulator that runs entirely in your browser. Build a topology, paste a vendor config, step packets one hop at a time, and see exactly why a route does — or doesn't — converge.
Why NetVerdict
Lab-grade behaviour, no lab.
Built for engineers who want to reason about packets, not babysit VMs.
Deterministic by design
Every packet, every queue, every timer is reproducible. Same inputs, same outputs — every time, on every machine.
Runs in your browser
The whole simulator is a TypeScript engine compiled to a static SPA. No backend, no telemetry, nothing leaves the tab.
Vendor-honest CLIs
Cisco-shaped IOS, Juniper Junos, NV-* reference platforms. The same commands you type in lab class actually do something here.
Step the packet, not the clock
Single-step a frame across L2/L3, watch ARP, RPF, OSPF LSAs and IP forwarding decisions resolve in front of you.
Free and open
Source-available, BSL 1.1 with a 4-year sunset to Apache 2.0. Self-host the static bundle anywhere.
Built for teaching
Save and share scenarios as a single URL. Hand a student a working misconfiguration in one click.
Platforms
Mix vendors in one topology.
Profiles describe both syntax and forwarding behaviour, so a Junos box and an IOS box converge OSPF the way the real ones would.
Built for the people who actually touch the wire.
Network engineers, instructors and students. Not slide decks.
Reproduce a production incident locally. Flip one config, see the convergence path change in milliseconds.
Hands-on lab practice for vendor certifications such as CCIE or JNCIE — drill OSPF, BGP and MPLS scenarios without burning hours on EVE-NG or paying for cloud labs. Not an official prep course; just an honest forwarding plane.
Hand out scenarios as URLs. Every student gets the exact same topology, the exact same packet trace, the exact same verdict.
Live in 30 seconds
Type real commands. See real packets.
A vendor-shaped CLI on top of an honest forwarding plane.
nv@core1> enable
nv@core1# configure terminal
nv@core1(config)# interface ge-0/0/0
nv@core1(config-if)# ip address 10.0.0.1/30
nv@core1(config-if)# no shutdown
nv@core1(config-if)# exit
nv@core1(config)# router ospf 1
nv@core1(config-router)# network 10.0.0.0/30 area 0
nv@core1(config-router)# end
nv@core1# show ip route ospf
Legend: O - OSPF, IA - inter-area
O 10.0.1.0/30 [110/2] via 10.0.0.2, 00:00:04, ge-0/0/0Get in touch
Talk to us.
Bug reports, feature ideas, teaching scenarios, licensing — we read every message.