필사 모드: Network Simulators & Emulators 2026 Complete Guide - Mininet · GNS3 · EVE-NG · Cisco Modeling Labs · Containerlab · NS-3 · OMNeT++ · Boson NetSim · Packet Tracer Deep Dive

Prologue — The Age of Virtual Routers

In the early 2010s, a network engineer stacked real Cisco 2811s under the desk and studied by plugging cables. In 2026, a single laptop spins up a 100-node BGP/MPLS topology in five minutes.

> **The center of gravity for network learning and validation has shifted entirely from hardware to virtualization.**

This article organizes the most-used network simulators and emulators of 2026 **by purpose**. From students preparing for CCNA, to SP engineers validating BGP/MPLS, to researchers building SDN controllers, to telecom engineers experimenting with 5G core — the tool spectrum is broad. Pick the wrong tool and you waste six months.

Chapter 1 · Simulator vs Emulator — The Fundamental Difference

These two words are often used interchangeably, but strictly speaking they are different.

| Aspect | Simulator | Emulator |

| --- | --- | --- |

| Definition | Models behavior abstractly | Runs real OS/firmware |

| Fidelity | As good as the model | Nearly identical to real gear |

| Performance | Fast (event-driven) | Heavy (VM/container) |

| Representatives | NS-3, OMNeT++, Packet Tracer | GNS3, EVE-NG, CML |

| Main use | Research, algorithm evaluation | Practical learning, pre-prod |

The key difference: **a simulator follows a model that says "in this situation it would behave this way." An emulator boots the actual IOS, Junos, or EOS image.**

Packet Tracer is an interesting boundary case. It accepts Cisco commands but does not run real IOS — it is a simulator. CML boots actual IOS XE/IOSv — it is an emulator. They look similar, but their behavior diverges in "complex scenarios."

Chapter 2 · Container-Based Network Labs

Virtual machines are heavy. Running 100 routers needs 200 GB of RAM. Container-based tools break this limit.

Mininet — The SDN Standard Lab

Started at Stanford, Mininet is **the de facto standard for SDN/OpenFlow research**. It builds hosts with Linux namespaces and switches with Open vSwitch. Hundreds of nodes run on a laptop.

sudo mn --topo linear,4 --controller remote,ip=127.0.0.1

This one line brings up a topology of four connected switches. Mininet's strengths are **speed and SDN friendliness**. Its weakness: **unsuitable for L3 routing or practical IOS learning** — purely for SDN research and education.

Mininet-WiFi — Extending into Wireless

An extension by Ramón Fontes from Spain that adds **wireless nodes, mobility, and interference models**. Often appears in 5G slicing research and IoT simulation.

Containerlab — The 2020s Powerhouse from Nokia

Open-sourced by Nokia in 2020, Containerlab is **the next-generation tool that spins up router/switch images as Docker containers**. Nokia SR Linux, Arista cEOS, FRRouting, and Cisco XRd all run as containers.

name: clab-demo

topology:

nodes:

spine1: {kind: nokia_srl, image: ghcr.io/nokia/srlinux}

leaf1: {kind: nokia_srl, image: ghcr.io/nokia/srlinux}

links:

- endpoints: ["spine1:e1-1", "leaf1:e1-1"]

One YAML file describes the topology, you can check it into Git, and you can run it in CI. **As of 2026 it is the fastest-growing network lab tool.**

Kathara · Antimony — Academic Docker Labs

Kathara, from Roma Tre University in Italy, is popular for BGP/OSPF teaching. Antimony shows up in SDN research labs. Both are simpler than Containerlab and specialized for education.

Chapter 3 · VM-Based Emulators — GNS3, EVE-NG, PNetLab

To run real IOS or Junos, you need a virtual machine. The Big Three in this space.

GNS3 — The Open-Source King

Started in 2008, GNS3 is **the flagship open-source network emulator**. It runs old Cisco IOS via Dynamips and IOSv, CSR, Junos via QEMU. The GUI is clean, the learning materials are abundant, and the Korean/Japanese communities are active.

**Strengths**: free, open source, rich material, GUI-friendly.

**Weaknesses**: configuration is tricky, heavy at large scale, you must source Cisco images yourself.

EVE-NG — The UK Commercial/Community Hybrid

UK-based EVE-NG offers two editions: **Community (free)** and **Professional (annual license)**. It runs all nodes on a single KVM server, and **provides console access via a web browser only**. It is more stable than GNS3 at scale.

Among CCIE candidates, **EVE-NG Pro is the de facto standard**. Cisco, Juniper, Palo Alto, F5, and Checkpoint images all run on it.

PNetLab — The EVE-NG Fork

Italian PNetLab forked from EVE-NG and expanded with **its own cloud hosting (Cloud My Lab)**. If your laptop is weak, you can rent a 100-node topology in the cloud by the hour.

UNetLab — Ancestor of EVE-NG

UNetLab is the predecessor of EVE-NG. Since 2017 it has effectively been absorbed into EVE-NG, but you may still see it referenced in older documentation.

Chapter 4 · The Cisco Camp — Packet Tracer, CML, DevNet Sandbox

Cisco has the thickest in-house learning ecosystem.

Cisco Packet Tracer — Where CCNA Starts

Packet Tracer is **Cisco's official free simulator**. Sign up for Cisco Networking Academy to get it. It is a simulator, so it is not real IOS, but **it covers 99% of the CCNA exam scope**. It is lightweight enough to run on an Intel MacBook.

**When to use it**: CCNA prep, undergraduate networking classes, foundational learning.

Cisco Modeling Labs (CML 2) — A Real Emulator

CML 2 is **a commercial emulator built by Cisco themselves**. IOS XE, IOS XR, and NX-OS virtual images are officially provided.

| Edition | Price (2026) | Node count |

| --- | --- | --- |

| CML Personal | $199/yr | 20 nodes |

| CML Personal Plus | $349/yr | 40 nodes |

| CML Enterprise | Inquire | Unlimited |

CCNP/CCIE candidates and enterprises that need an official Cisco license are the main users.

Cisco DevNet Sandbox — Real Gear for Free

DevNet Sandbox is **Cisco's free cloud lab**. Real Catalyst, Nexus, ACI, and Webex devices are allocated for a limited time at no cost. If buying CML feels expensive, start here.

Cisco Modeling Labs Personal — Best Value

Formerly called VIRL Personal Edition. For $199/year you get 20 nodes, which **makes it the best value pick for individuals preparing for CCNP**.

Chapter 5 · Juniper · Arista · Other Vendors

Cisco is not the whole world.

Juniper vLabs — Free

Juniper offers **vLabs for free**. Access via a web browser and you get vMX, vSRX, and vQFX in pre-staged topologies. Plenty for JNCIA/JNCIP study.

Arista vEOS · cEOS — Free Download

Arista distributes vEOS (VM image) and cEOS (container image) **free with developer registration**. They are widely used for ACE certification prep and for validating data-center EVPN/VXLAN.

Aruba Sandboxes

HPE Aruba provides Aruba Central sandboxes for its users. Useful for learning ArubaOS-CX.

Nokia SR Linux · Mikrotik RouterOS

Nokia SR Linux is Containerlab-friendly and free. Mikrotik RouterOS ships as a CHR (Cloud Hosted Router) image, free or low-cost — **a favorite for studio-apartment labs**.

Chapter 6 · Academic / Research Simulators — NS-3, OMNeT++, SimPy

If you are writing a paper, the field is different.

NS-3 — The Standard for Research Simulators

NS-3 is **the de facto standard in networking research papers**. You write scenarios in C++/Python and simulate via discrete events. When evaluating a new TCP, MAC, or routing variant, NS-3 shows up.

NS-3's strength is its **module ecosystem** — Wi-Fi, LTE, 5G NR, mmWave, and Vehicular (V2X) modules are all well-maintained.

NS-2 — Legacy

NS-2 is the generation before NS-3. Many papers used NS-2 through the mid-2010s, but as of 2026 the field has effectively migrated to NS-3. You only touch NS-2 when reading old code.

OMNeT++ — Discrete-Event Powerhouse

OMNeT++ is a C++ discrete-event simulator that originated in Hungary. With the **INET Framework** on top, you get TCP/IP, MAC, and 5G. In academia, especially in Europe, it stands shoulder-to-shoulder with NS-3.

SimPy — When Python Is Enough

If you do not need packet-level simulation but only an **abstract model of queueing or system behavior**, Python's SimPy is enough. Common in classrooms.

OPNET → Riverbed Modeler — Commercial

OPNET started in 1986 as a commercial simulator and became **Riverbed Modeler** after Riverbed acquired it. A free student edition exists, but academia itself has largely moved to NS-3 and OMNeT++.

Chapter 7 · SDN / OpenFlow Specific

SDN has its own tool stack.

Open vSwitch (OVS) — The Virtual-Switch Standard

OVS is **the Linux kernel virtual switch**. It supports OpenFlow natively. It is the default switch in Mininet and the foundation of every SDN experiment.

Ryu · POX · ONOS · OpenDaylight — Controllers

| Controller | Language | Position |

| --- | --- | --- |

| Ryu | Python | NTT, education |

| POX | Python | Academia, beginner |

| ONOS | Java | ON.Lab, telco |

| OpenDaylight | Java | Linux Foundation, enterprise |

In undergraduate SDN courses, POX and Ryu dominate. In production and telco SDN, ONOS and OpenDaylight are the standard.

Chapter 8 · Wireless · 5G Simulators

Wireless and 5G are yet another world.

NS-3 LTE / 5G Modules

NS-3's **LENA module** (LTE) and **5G-LENA** (5G NR) are the workhorses of academic wireless research. Channel models, handover, and QoS are all included.

5G-Sim-V2X — Vehicular Simulation

For autonomous-vehicle and V2X simulation, integrated tools like 5G-Sim-V2X (NS-3 + SUMO traffic simulator) are used.

OAI (OpenAirInterface) — Open-Source 5G

OAI is **an open 5G stack from Eurecom**. Both RAN and core are open source. Connect it to actual USRP hardware and you can run a real 5G cell.

srsRAN · Open5GS — Lightweight 5G

srsRAN (Ireland's SRS company) and Open5GS (rooted in Korea's NeoPlane) are **lighter alternatives to OAI for bringing up 5G**. Open5GS was led by a Korean developer and is popular in Korean telecom academia.

Chapter 9 · Cloud · SD-WAN Simulation

The SD-WAN and multi-cloud era needs new tools.

Aviatrix CoPilot

Aviatrix is a multi-cloud networking platform, and CoPilot is its virtual console. It provides sandboxes that mimic real AWS/Azure/GCP infrastructure.

VMware VeloCloud Sandbox

VMware's SD-WAN solution (now a Broadcom subsidiary). Sales-target customers get demo sandboxes for a limited period.

Versa Networks · Fortinet Secure SD-WAN

These vendors also run their own demo environments, usually accessed through sales channels.

Chapter 10 · Real-Network Telemetry — Monitoring and Analytics

After learning, you need monitoring tools.

ntopng — Free Traffic Analysis

ntopng is **a real-time traffic analyzer** from Italian company ntop. It ingests NetFlow, sFlow, and IPFIX and renders dashboards. An open-source/community edition is available.

NetFlow Analyzer · PRTG · SolarWinds NPM

ManageEngine NetFlow Analyzer, Paessler PRTG, and SolarWinds NPM are **the big three of enterprise network monitoring**. SolarWinds has tightened security significantly since the 2020 Sunburst incident.

Grafana + Telegraf + InfluxDB — The Open-Source Stack

The most common open-source monitoring stack in 2026. It ingests SNMP/gNMI data and renders Grafana dashboards. **Treat it as the modern NetOps standard.**

Chapter 11 · Cloud Lab Platforms

If your laptop is weak, rent the cloud.

Cisco DevNet Sandbox

Already mentioned in Chapter 4, but worth restating: **Cisco DevNet Sandbox lends you real Cisco gear for free.** There are time-slot constraints, but it is enough for CCNP/CCIE study.

Juniper vLabs

Juniper runs the same kind of free cloud lab. Plenty for certification study.

NRELabs — Antidote-based

Started by former Nicira engineers, NRELabs is **an open platform for SDN/NetDevOps hands-on practice in the browser**. Free slots are available.

Cloud My Lab (PNetLab Cloud) · Tackle Box · NetworkLessons.com Labs

These are **paid cloud labs you rent by the hour**. EVE-NG/PNetLab topologies are pre-installed, so even with a weak PC you can immediately fire up a CCIE-grade topology.

Chapter 12 · Certification-to-Tool Mapping

If you are studying for certification, tool choice is obvious.

Cisco — CCNA / CCNP / CCIE

| Certification | Recommended tool |

| --- | --- |

| CCNA | Packet Tracer + DevNet Sandbox |

| CCNP Enterprise | CML or EVE-NG + DevNet |

| CCIE | EVE-NG Pro + CML + cloud lab |

Juniper — JNCIA / JNCIP / JNCIE

For Juniper, the orthodox combo is **vLabs (free) + EVE-NG/GNS3 with vMX images**. vLabs alone covers a large portion of JNCIE prep.

Arista — ACE

Arista's vEOS and cEOS are free, and there is a separate learning site called **EOS-Sandbox**. Learning costs almost nothing.

CompTIA Network+

CompTIA Network+ is vendor-neutral, so **Packet Tracer or GNS3 + Linux routing** is plenty. The exam is theory-heavy.

Chapter 13 · Use-Case to Tool Matrix

Quick answer to "I want to do X, what do I use?"

| Purpose | First choice | Alternative |

| --- | --- | --- |

| CCNA prep | Packet Tracer | DevNet Sandbox |

| CCNP/CCIE prep | CML or EVE-NG | GNS3 |

| SDN development | Mininet | Containerlab |

| Academic paper (TCP/MAC) | NS-3 | OMNeT++ |

| 5G research | OAI · srsRAN | NS-3 5G-LENA |

| Pre-production validation | Containerlab + CML | GNS3 + EVE-NG |

| Multi-vendor topology | EVE-NG | Containerlab |

| CI integration | Containerlab | Kathara |

| Undergraduate lecture | Packet Tracer | Kathara |

| Studio-apartment self lab | Mikrotik CHR + GNS3 | Containerlab |

Principle: **simulators are easier to learn, emulators are closer to reality. Own both.**

Chapter 14 · The Korean Networking Community

If you are serious about studying networks in Korea, these communities are worth joining.

- **CCIE Korea** — community of Korean CCIE holders. Active on Facebook and KakaoTalk.

- **NetMaster Korea** — Korean network-engineer community site.

- **Cisco Korea Connect** — official user group run by Cisco Korea.

- **TTA (Telecommunications Technology Association)** — Korea's standards body. Certifications, training, standardization.

- **NETCONF/YANG Korea Working Group** — for modern network-automation enthusiasts.

- **DevOps Korea** — also covers NetOps/NetDevOps.

Korean-language EVE-NG and GNS3 tutorial blogs are also plentiful — Naver Blog and Tistory have a lot of material.

Chapter 15 · The Japanese Networking Community

Japan has an exceptionally strong operator community.

- **JANOG (Japan Network Operators' Group)** — the Japanese equivalent of NANOG. Two conferences per year.

- **Cisco Japan** — runs its own user community.

- **NTT Communications · NTT Labs** — strong industry-academia community.

- **InternetWeek (hosted by JPNIC)** — held in Tokyo every November. A unified conference for standards, operations, and policy.

- **IPv6 Promotion Council** — Japan's IPv6 promotion body.

Japanese engineers discuss actively on Twitter/X — along with the JANOG mailing list, it is one of the two main channels for Japanese networking information.

Chapter 16 · Hardware Labs for the Truly Serious

Virtual environments are enough for most cases, but some scenarios need real gear.

- **Used Cisco/Juniper on eBay/Mercari/Yahoo Auctions** — a Catalyst 2960/3560 is $50-100, an ISR 2811 is roughly parts value.

- **NETGEAR ProSAFE / MikroTik** — affordable enterprise-grade. A MikroTik RB5009 is around $250 and runs full BGP/OSPF.

- **Ubiquiti EdgeRouter / UniFi** — popular for home use. A bit simple for learning.

- **Raspberry Pi + FRRouting** — a Pi 4/5 + FRR is a BGP-capable lab. Extremely cheap.

For a serious studio-apartment lab, **3 MikroTik routers + 1 switch + 3 Raspberry Pis** is the best value combo. You can build a small SP-style network for under $1000.

Chapter 17 · Intersection with Network Automation

A 2026 network engineer must also know automation.

- **Ansible Network Collection** — rich modules for Cisco/Juniper/Arista.

- **Nornir** — Python-based, a faster automation framework than Ansible.

- **Netmiko · NAPALM** — Python libraries to SSH/NETCONF into routers.

- **NetBox** — network asset and IPAM management (Source of Truth).

- **Nautobot** — NetBox fork. More active development.

- **Cisco NSO (Network Services Orchestrator)** — multi-vendor service orchestration.

- **Juniper Apstra** — intent-based data-center operations.

- **Batfish · Forward Networks** — network-intent verification and simulation.

Recommended learning path: bring up topologies with Mininet/Containerlab, configure them with Ansible/Nornir, and manage assets with NetBox — **the basic cycle of modern NetDevOps**.

Chapter 18 · CI/CD and Network Validation

The biggest change for ops teams in 2026 is that **network configurations are validated in CI**.

1. Engineer opens a config-change PR in Git

2. CI brings up a Containerlab topology (staging replica)

3. CI applies the new configuration

4. CI runs automated ping/traceroute/BGP-session validation

5. CI runs Batfish for intent validation (e.g., "DMZ unreachable from internal")

6. All checks pass → merge → auto-deploy to production

The keystone tools for this workflow are **Containerlab + Batfish + Ansible/Nornir**. Real cloud companies already operate this way.

Chapter 19 · Pitfalls and Cautions

Common mistakes when adopting tools.

- **Image licensing** — Cisco IOSv, CSR1000v, and IOS XRv require licenses. Do not just upload them to EVE-NG/GNS3. CML is a proper licensed product.

- **Hardware resources** — a 100-node EVE-NG lab demands 64 GB RAM and a fast SSD. If a laptop is not enough, move to a cloud lab.

- **Simulator limits** — Packet Tracer accepts some commands that do not actually behave correctly. After passing, validate on real gear, CML, or EVE-NG.

- **NS-3 time investment** — NS-3 has a steep learning curve. Two to four weeks to your first simulation is typical. Do not start it with a paper deadline looming.

- **Container vs VM** — Containerlab is fast, but it cannot reproduce BIOS/HW-related behavior. Some scenarios need GNS3 or EVE-NG.

Chapter 20 · The Future — Where Things Go After 2026

Predicting the network-virtualization direction over the next two to three years:

- **eBPF-based data-plane simulation** — as Cilium/Calico's eBPF standardizes, container-network simulators will become eBPF-friendly.

- **AI-driven config generation and validation** — workflows where Claude/GPT generate Cisco CLI and Batfish validates them.

- **Digital twins** — keeping a real-time replica of a live production network in a simulator.

- **Maturing 5G/6G modules** — an NS-3 6G NR module is expected around 2027.

- **WebAssembly-based network simulators** — tools that spin up topologies directly in the browser.

Virtualization tools will keep getting lighter, AI-integrated, and blur the line between "the running network" and "the lab."

Chapter 21 · A Practical 3-Month Learning Roadmap

A three-month roadmap for someone starting from scratch.

**Month 1 — Foundations**

- Install Packet Tracer → watch a CCNA course → build five core topologies by hand

- Install Wireshark → packet-analysis basics

- Linux network basics (`ip`, `ss`, `tcpdump`, `nmap`)

**Month 2 — Emulation**

- Install GNS3 or EVE-NG Community

- Build multi-AS BGP/OSPF topologies

- Use Cisco DevNet Sandbox to feel real gear

- Begin automation with Ansible or Netmiko

**Month 3 — Modern Stack**

- Use Containerlab to bring up Nokia/Arista topologies

- Manage assets with NetBox or Nautobot

- Validate intent with Batfish

- Publish a "lab topology repo" of your own on GitHub

After three months, not only is CCNA within reach, but you can talk about modern NetDevOps in an interview.

Chapter 22 · Conclusion — Tools Are Means, Thinking Is Essence

GNS3, NS-3, or Containerlab — tools are ultimately **aids to visualize network behavior in your head**. Spending 100 hours in a simulator means nothing if you cannot sketch the OSI 7 layers from memory.

The principles are simple:

1. **Packet Tracer is enough for CCNA.**

2. **CML or EVE-NG for CCNP/CCIE.**

3. **Mininet, NS-3, OMNeT++ for SDN and research.**

4. **Containerlab + Ansible + NetBox for modern NetDevOps.**

5. **If unsure, start with Cisco DevNet Sandbox.**

Virtual environments are fast and cheap. Do not let tools become an excuse to delay learning.

Chapter 23 · References

- Mininet — http://mininet.org/

- Mininet-WiFi — https://github.com/intrig-unicamp/mininet-wifi

- Containerlab — https://containerlab.dev/

- Kathara — https://www.kathara.org/

- GNS3 — https://www.gns3.com/

- EVE-NG — https://www.eve-ng.net/

- PNetLab — https://pnetlab.com/

- Cisco Packet Tracer — https://www.netacad.com/courses/packet-tracer

- Cisco Modeling Labs — https://developer.cisco.com/modeling-labs/

- Cisco DevNet Sandbox — https://developer.cisco.com/site/sandbox/

- Juniper vLabs — https://jlabs.juniper.net/vlabs/

- Arista vEOS — https://www.arista.com/en/support/software-download

- NS-3 — https://www.nsnam.org/

- OMNeT++ — https://omnetpp.org/

- INET Framework — https://inet.omnetpp.org/

- OpenAirInterface (OAI) — https://openairinterface.org/

- srsRAN — https://www.srslte.com/

- Open5GS — https://open5gs.org/

- ONOS — https://opennetworking.org/onos/

- OpenDaylight — https://www.opendaylight.org/

- Open vSwitch — https://www.openvswitch.org/

- Batfish — https://www.batfish.org/

- NetBox — https://netbox.dev/

- Nautobot — https://www.nautobot.com/

- FRRouting — https://frrouting.org/

- JANOG — https://www.janog.gr.jp/

- ntopng — https://www.ntop.org/products/traffic-analysis/ntop/

Closing

The future of networking lies on top of virtualization, automation, and AI. The starting point for all of that is **the ability to experiment safely with simulators and emulators**.

Install tools, build with them, break them — keep doing it until they feel native. A 2026 network engineer brings up 100 routers on a desk, manages them as code, and validates them with AI. Get started — the age of virtual routers is here.