VPNs Explained

VPNs Explained

1 min readPublished 22 Jul 2026

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A VPN (Virtual Private Network) creates an encrypted tunnel across an untrusted network like the internet, so data travels privately between sites or remote workers and the office.

Interactive explainer

How a VPN Tunnel Works

An encrypted tunnel across the untrusted internet.

Tap or hover a part to learn more.

Remote user / site

The endpoint.

A remote worker (remote-access VPN) or a whole branch office (site-to-site VPN) starts the connection. Without a VPN their traffic would cross the internet in the clear.

Check your understanding

1. What two things does a VPN primarily provide?

2. Which VPN type connects two whole networks?

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VPNs Firewalls CompTIA Network+

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The core idea

Site-to-site VPNs connect whole networks (e.g. branch to head office).
Remote-access VPNs connect individual users to the corporate network.
VPNs combine encryption (confidentiality) with authentication (proving identity).

How it works in practice

IPsec is common for site-to-site; SSL/TLS VPNs suit remote users via a browser or client.
Split tunnelling sends only some traffic through the VPN.
Strong, modern protocols matter — avoid legacy PPTP.

Common mistakes

Using weak or outdated VPN protocols.
Misconfiguring split tunnelling and leaking traffic.
Assuming a VPN alone makes everything secure.

Why it matters for your career

VPNs are core to Network+ and Security+ and to supporting remote and hybrid workforces — a daily reality for IT teams.

Technical interview questions

What is the difference between site-to-site and remote-access VPNs?
What does a VPN provide?
Why avoid PPTP?

Practice questions

What connects two whole networks? (Site-to-site VPN)
What two things does a VPN provide? (Encryption + authentication)
Common site-to-site protocol? (IPsec)

Where this fits in your networking journey

This is one concept in the Networking Fundamentals path, which leads into CompTIA Network+ and Cisco CCNA. When this clicks, review Firewalls and continue with Wireless Networking.

Practise with Missiora

AI Interview™ — rehearse networking interview questions with scored feedback.
Career Coach™ — build a fundamentals → certification → job plan.
Job Intelligence™ — see which networking skills real adverts demand.

Interview Intelligence

How this topic actually shows up in interviews — and how to demonstrate you understand it.

Why employers ask about this

Remote work made VPNs essential; interviewers check you understand encryption and VPN types.

Technical questions

What does a VPN provide?+

Confidentiality (encryption) and authentication for traffic crossing untrusted networks.

Site-to-site vs remote-access VPN?+

Site-to-site links whole networks; remote-access connects an individual user in.

Behavioural questions

Describe supporting remote workers on VPN.+

Explain patiently checking client config, credentials and connectivity.

Real-world scenarios

“A remote user's VPN connects but they can't reach internal resources.”+

Expected answer: Check routing/split-tunnel config and internal firewall/DNS.

Common candidate mistakes

•Using weak/legacy protocols like PPTP.
•Misconfiguring split tunnelling.

Practise in AI Interview™Rehearse these questions, scored.Plan with Career Coach™A personalised path to your goal.Evidence it in Career Passport™Prove this skill to employers.

Employability Intelligence

Where this knowledge takes you — the jobs, skills and certifications it feeds into.

Relevant roles

Network AdministratorSecurity EngineerIT Support Technician

Skills you're proving

VPNsIPsec/SSLEncryptionRemote access

Recommended certifications

CompTIA Security+CompTIA Network+

Career progression

IT Support → Network Administrator → Security Engineer.

What employers expect

That you can support and reason about secure remote access.

Frequently asked questions

What is vpns in networking?

A VPN (Virtual Private Network) creates an encrypted tunnel across an untrusted network like the internet, so data travels privately between sites or remote workers and the office.

What is the difference between site-to-site and remote-access VPNs?

Site-to-site VPNs connect whole networks (e.g. branch to head office). Remote-access VPNs connect individual users to the corporate network.

Do I need this for Network+ or CCNA?

Yes — VPNs is a core concept in CompTIA Network+ and Cisco CCNA. Understanding it here first makes the certification material much easier.

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Missiora is an AI Employability Intelligence platform. Our resources are researched and reviewed by the Missiora team to help you measure, improve and prove your career readiness.