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Unlimited labs · 24x7 · nothing to install

The #1 Network Simulator. Learn by Doing, One Task at a Time.

Routers, switches and firewalls that behave like the real thing, in your browser. Type the commands, watch every packet on the wire, and let live task checks prove your network works. CCNA to CCIE, Juniper, Fortinet, Palo Alto and more.

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No credit card. First module of every track + 3 labs, free.

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NK-OS · lab-ospf-01
UPFULLFULLPC1192.168.1.10R110.0.12.1R210.0.12.2R310.0.23.3

The lab ends with OSPF neighbours in FULL state and a successful ping from PC1 to R3.

OSPF neighbour FULLping 100% (5/5)capture · Gi0/0 · 128 pktstask 3/3 verified
  • 2350+hands-on labs
  • 83certification tracks
  • 24x7labs open, every day
  • 0installs. Just a browser
CiscoJuniperPalo AltoFortinetAristaArubaCheck PointF5MikroTikVersaNVIDIACompTIACiscoJuniperPalo AltoFortinetAristaArubaCheck PointF5MikroTikVersaNVIDIACompTIA

Real behaviour

Routing tables, neighbour states and NAT translations change exactly like on real hardware.

Checked, not watched

Tasks tick only when the network really works. No keyword matching, no answer keys.

Career built in

Resume keywords, a train-style roadmap, mock exams and certificates come with every track.

From the patch cable to the command line.

At the console

Think through the network. Then make it work.

Build a branch network, configure its devices and follow the traffic. Use the console and packet capture together to understand why a connection works, or why it fails.

Configure the devices

Work with interfaces, VLANs, routes and firewall policies.

Inspect the packets

Read the headers and prove what happens on the wire.

Build your own lab

More than labs: practise like you work

Design a network, plan your path, work real tickets and get a resume that matches the jobs.

INTERNET 8.8.8.8FW1R1SW1SW2PC1PC2PC3PC4

Design your own lab

Drag routers, firewalls and switches onto a canvas, cable them and watch traffic flow through the internet cloud.

Build a lab
  1. 1CCNA
  2. 2ENCOR
  3. 3ENARSI
  4. 4SPCOR
  5. 5Automation
Goal: Network Engineer, 9 months0%

A roadmap built for you

Tell us your goal and see the tracks, in order, that get you to the role.

Plan my roadmap
INC0010432 · P2New

Branch users cannot reach the internet

SLA28 min left
  • show ip route on R1
  • Found: missing NAT overload
  • ip nat inside source list 1 interface Gi0/1 overload
+120 XP

Work real NOC tickets

Take a ticket, find the root cause on the devices, fix it before the SLA runs out and earn XP.

Take a ticket
38
ATS score
Keywords from the job post
OSPFBGPVLANNATFortiGatePython

A resume that gets shortlisted

Upload your resume, see its ATS score and add the keywords that jobs ask for.

Check my resume

New · Flashbooks

Read every lesson like a real book

Open any chapter full screen as a two-page Flashbook. Pages turn with a real paper sound, and the highlighter saves the lines that matter to My Notes, ready for revision before your exam or interview.

  • Two-page spreads, full screen, three paper tones
  • Page-turn sound, arrow keys and swipe
  • Highlight in four colours and add your own note
  • My Notes: search every highlight across all tracks
  • Text cannot be copied; your highlights are always saved
Open a Flashbook
certification tracks

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Every module has reading, console labs, a quiz and scenario questions, in English and Hinglish.

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Labs

Hands-on network labs in your browser

Every lab runs in your browser — no installs, no GNS3, no packet tracer. Type IOS commands, watch the wire, get checked.

View all labs (2630+)
Packet Studio

See inside every packet

A Wireshark-style capture of real frames: Ethernet, ARP, IPv4, ICMP, TCP, UDP, DNS, DHCP and OSPF. Click any field to see its bits, its bytes and what it does.

Packet Studio
capture · R1 Gi0/0
110.0.12.1224.0.0.5OSPF
2192.168.10.108.8.8.8DNS
3192.168.10.10203.0.113.80TCP
4203.0.113.80192.168.10.10TCP
510.0.12.14.4.4.4ICMP
64.4.4.410.0.12.1ICMP
Checksums, lengths and flags are computed exactly like on a real wire.
How a lab works

How a lab works

Three things happen in every lab. None of them is a video.

Try free

  1. Configure

    Type IOS-style commands on NK-OS routers. ? help, Tab completion and short forms work like the real CLI.

  2. Watch the wire

    Links turn green when OSPF goes FULL. Capture any link and read the packets, byte by byte.

  3. Get checked

    Tasks tick themselves when the network really works, not when you type a keyword.

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Your next job interview has a console in it.

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CONFIG

Unlimited practice labs, 24x7, in your browser. Built by Network Kings for engineers who want to be CLI Kings.

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Pricing & access rules — INR, USD and VPN
  1. Paid in INR? Use the labs from inside your region. INR pricing is for learners in India, Nepal, Pakistan, Bhutan and other developing countries, decided by your IP country. If you pay in INR and then connect through a VPN, proxy or an IP outside your region, the labs will not let you do anything. If you study from outside these regions, or want to use a VPN, please pay in USD.
  2. Why USD pricing is a little higher. Our lab servers are hosted in the US, so every lab session runs on US compute, storage and virtual network devices billed to us in USD. We deliver through a global CDN and multi-region routing to keep consoles fast for learners worldwide, which adds a recurring cost per active user. International payments also carry gateway, currency-conversion and compliance fees. On top of that, our marketing spend in international markets is about 10x what we spend in India, and a small share of that is reflected in USD pricing.
  3. One account, one region. Your plan is tied to the currency and region you paid in. Sharing an account across regions, or masking your location to get INR pricing, can lock the account without a refund. Travelling or changing network? Contact support before you log in.

CONFIG by Network Kings — an educational IT simulation platform for learning purposes only. It is not Cisco IOS, Junos, FortiOS or PAN-OS and contains no Cisco, Juniper, Fortinet or Palo Alto Networks software. Cisco, IOS, CCNA, CCNP, Juniper, JNCIA, JNCIS, JNCIP, Fortinet, FortiGate, FortiOS, NSE, Palo Alto Networks, PAN-OS and PCNSE are trademarks of their respective owners. Network Kings is not affiliated with or endorsed by Cisco Systems, Inc., Juniper Networks, Inc., Fortinet, Inc. or Palo Alto Networks, Inc.