The Boson NetSim alternative
for when the guided labs run out.
NetSim is a genuinely good study product: 85 guided CCNA labs, no images to find, works on day one. It is also $179 a year, Windows only, and a simulation - it reproduces the commands Boson wrote, not the firmware Cisco ships. The day you want to build your own topology, that difference stops being academic.
Simulation and emulation are not the same word with different marketing. A simulator like NetSim reimplements device behaviour in its own code: someone at Boson decided what show ip route prints and what happens when a timer expires. That is why it starts instantly, needs no Cisco images, and never leaks memory - and also why it only knows the commands and scenarios they built. An emulator runs the vendor's actual firmware on virtual hardware. It is slower to boot and you have to bring your own images, but the device is the device: every command, every quirk, every unhelpful error message. For guided exam practice, simulation is enough. For designing something, or for anything Boson did not anticipate, it is not.
Perfect for the exam.
Then what?
It is a simulation, so it only knows what was written into it
Type a command outside the supported set and you get an error the real device would never give you. Build a topology Boson did not anticipate and behaviour drifts from the hardware. That is fine while you are following their lab guide, and a problem the moment you are testing your own idea.
Windows only, one machine, one licence
NetSim is a Windows desktop application. On a Mac or a Linux box you are running a Windows VM to run a simulator. There is no shared lab, no link to send an instructor, no server the whole class connects to - it is software on one person's laptop.
Cisco only, and only some of Cisco
NetSim covers the Cisco exam track and nothing else. No Juniper, no Arista, no Linux hosts, no firewalls from anybody. Real jobs and real interviews are multi-vendor, and increasingly the interesting parts are on the boxes NetSim does not model.
The subscription ends and so does the lab
At around $179 a year per exam track, the labs stop when the licence does. Nothing you built carries forward into a tool you keep, and there is no export into anything else - the topologies live in Boson's format on Boson's terms.
NetSim and netplex.,
line by line.
| Feature | Boson NetSim about $179/year |
netplex. Associate, free |
|---|---|---|
| How devices run | Simulated behaviour | Real vendor firmware under QEMU |
| Images needed | None - built in | You bring your own |
| Guided, marked lab exercises | About 85 for CCNA | No - you build the topology |
| Time to first lab | Minutes | Longer - images first |
| Runs on macOS or Linux | No - Windows only | Yes - any browser |
| Commands outside the exam syllabus | Often unsupported | Whatever the firmware supports |
| Vendors covered | Cisco only | Cisco, Juniper, Arista, Fortinet, Linux and more |
| Your own topology designs | Limited | Unlimited - drag and wire anything |
| Node limit | Fixed per lab | None - your hardware decides |
| Share a running lab | No | Send a link |
| Packet capture | Simulated view | Real frames, real pcap for Wireshark |
| Automation and API | No | REST, CLI, Terraform, Ansible |
| Cost after year one | Renew per exam track | Free tier stays free |
Pricing is Boson's published list price for a single NetSim exam track and moves from time to time - check their site for today's figure. The simulation and emulation distinction is Boson's own description of the product, not a criticism we invented.
The short version: NetSim teaches the exam, netplex. teaches the network.
If you are three weeks from a CCNA and want marked exercises with no setup, buy NetSim - it is well made and it does that job better than we do. If you want to keep the lab after the exam, put a Juniper box next to the Cisco one, or test a design nobody wrote a guided exercise for, you need real firmware. The free tier costs nothing to try.
Straight with you - where NetSim still wins
NetSim needs no images. That is a genuinely large advantage and we will not pretend otherwise: sourcing legitimate Cisco IOS images is the single hardest part of running a real emulator, and Boson removes it entirely by writing the behaviour themselves. Their guided labs are structured, marked and mapped to exam objectives, which is real instructional design - netplex. gives you a canvas and no curriculum. It starts in seconds where a QEMU router takes a minute or two. And for pure CCNA memorisation, the simulation is accurate enough that the difference will not cost you marks. If you have no images and a deadline, NetSim is the right purchase.
The real thing, on any machine.
Actual firmware, any vendor, in a browser tab, with no annual renewal.
Real firmware, real quirks
Every command the image supports works, including the ones no exam ever asks about.
No Windows requirement
The emulator runs on a Linux host. Your machine needs a browser, so Macs and Chromebooks are in.
Multi-vendor from the start
Cisco next to Juniper next to Arista next to a Linux host, wired together and capturable.
Topologies you invent
Drag any node, wire any link. Nothing has to have been written as an exercise first.
Real packet capture
Capture actual frames off a link and open the pcap in Wireshark - not a rendering of what traffic would look like.
Keeps working when you stop paying
The free Associate tier has no node limit and no expiry.
NetSim questions,
answered honestly.
Weighing up another tool? Read the side-by-side.
vs Cisco Packet Tracer
Simulated device behaviour versus real IOS, and the exact point where the simulation stops keeping up.
vs Huawei eNSP
A Windows-only simulator Huawei has stopped developing, and a Pro version only partners can get.
vs EVE-NG
The 7-node Freemium cap, the fixpermissions ritual, the MAC-locked Pro licence - and what changes without them.
vs GNS3
The desktop GUI plus a separate VM, versus one browser tab that anyone on your network can open.
vs Cisco CML
Cisco's own images and per-seat licence, next to a multi-vendor platform with a free tier.
The EVE-NG node limit
7 nodes on Freemium, 1,024 on Pro, none here - and why the cap exists at all.
Keep the lab
after the exam.
Real firmware, any vendor, in a browser tab. Free tier, no node limit, nothing to install on your laptop.
Last reviewed September 2026 · Spotted something out of date? Tell us.