The reference desk
Briefs
Plain, correct explainers on enterprise VPN architecture and the protocols underneath — newest first. Each brief is dated and re-checked when a standard, protocol or common appliance changes.
What Is FortiClient? Fortinet's VPN and Endpoint Agent
FortiClient is Fortinet's endpoint agent, best known as the VPN client for FortiGate firewalls. What it does, IPsec vs SSL VPN modes, and the security context IT should know.
Read →BRIEF-09Aug 12, 2026VPN Protocols Compared for IT: IPsec, IKEv2, SSL, WireGuard
The VPN protocols an IT team actually chooses between — IPsec, IKEv2, SSL/TLS, WireGuard and the retired PPTP and L2TP — compared on transport, use case and encryption.
Read →BRIEF-08Aug 8, 2026WireGuard for Business: Strengths, Limits and Tailscale
WireGuard is a fast, modern VPN protocol with a tiny codebase. What makes it good for business networks, where it needs help, and how Tailscale builds on it.
Read →BRIEF-07Aug 3, 2026Zero Trust vs VPN: What ZTNA Changes for Remote Access
Zero trust grants per-application access after verifying identity and device; a VPN grants network access. How ZTNA differs, and why most teams run both for now.
Read →BRIEF-06Jul 29, 2026Remote-Access VPN: How It Works for a Distributed Workforce
A remote-access VPN connects individual devices to the corporate network. How the client and gateway work, full vs split tunnel, and the protocols used.
Read →BRIEF-05Jul 24, 2026What Is VPN Passthrough? And Why It Barely Matters Now
VPN passthrough is a router feature that lets VPN traffic cross NAT. What it did for PPTP, L2TP and IPsec, and why NAT traversal made it mostly obsolete.
Read →BRIEF-04Jul 20, 2026Site-to-Site VPN: How It Works and When to Use It
A site-to-site VPN joins whole networks with one gateway-to-gateway tunnel. How it works, policy-based vs route-based, and how cloud providers implement it.
Read →BRIEF-03Jul 15, 2026IPsec vs SSL VPN: How to Choose for the Enterprise
IPsec and SSL VPN solve remote access differently. How each works, where they beat the other, and how to choose per use case rather than by which is 'more secure'.
Read →BRIEF-02Jul 11, 2026What Is a VPN Concentrator? Do You Still Need One?
A VPN concentrator is a device built to terminate many remote-access tunnels at once. What it does, how it compares to a firewall or router, and whether it still makes sense.
Read →BRIEF-01Jul 7, 2026VPN Split Tunneling: What It Is and When to Use It
Split tunneling routes only some traffic through the VPN and the rest through the local connection. How it works, the three types, and the security trade-offs.
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