VPN

/ˈel-tuː-tiː-piː/

n. “A tunnel that forgot to bring a lock.”

L2TP, short for Layer 2 Tunneling Protocol, is a networking protocol designed to create virtual tunnels across IP networks. Its job is not secrecy, not encryption, and not trust — its job is encapsulation. L2TP takes packets from one place, wraps them neatly, and delivers them somewhere else as if they had always belonged there.

Developed in the late 1990s as a merger of Cisco’s L2F and Microsoft’s PPTP ideas, L2TP lives at layer 2 of the OSI model. That placement allows it to carry protocols like PPP transparently, which made it attractive for dial-up ISPs, early broadband providers, and enterprise remote-access systems that wanted flexibility without rewriting everything.

What L2TP very intentionally does not do is encryption. On its own, it provides no confidentiality, no integrity guarantees, and no authentication beyond basic session handling. This is not a flaw so much as a design boundary — L2TP assumes someone else will handle security.

That “someone else” is almost always IPSec. When paired together as L2TP/IPSec, the two form a familiar VPN stack: L2TP builds the tunnel, while IPSec encrypts, authenticates, and protects the traffic flowing through it. The result is a secure VPN connection that is widely supported across operating systems, routers, and network appliances.

This division of labor explains both the strength and the awkwardness of L2TP. Because it relies on IPSec, it inherits strong cryptography when configured correctly — typically using AES for encryption and hashes like SHA1 or SHA256 for integrity. But it also inherits complexity, multiple negotiation phases, and a fondness for UDP ports that firewalls love to block.

In practice, L2TP/IPSec became popular because it was “good enough” and everywhere. Windows, macOS, iOS, Android, and countless routers support it out of the box, often with minimal configuration. For administrators, that ubiquity mattered more than elegance.

Performance, however, is not L2TP’s strong suit. Double encapsulation — first by L2TP, then by IPSec — adds overhead and latency. Compared to leaner designs like WireGuard or even OpenVPN, it feels heavy, chatty, and stubbornly old-school.

There are also practical limitations. L2TP/IPSec struggles behind strict NAT environments and restrictive networks, where required ports are filtered or modified. Unlike OpenVPN, it cannot easily disguise itself as HTTPS traffic, making it more detectable and more likely to fail in hostile network conditions.

Still, L2TP refuses to disappear. It persists in corporate environments, legacy documentation, and “just make it work” setups where compatibility outranks performance. When someone says they’re using a VPN built into their operating system without installing anything extra, L2TP/IPSec is often what they mean.

L2TP is not clever. It is not modern. It is not fast. But it is honest about its role. It builds tunnels. It leaves security to others. When paired wisely, it works. When misunderstood, it leaks assumptions like an unsealed pipe.

Considered serviceable. Rarely loved. Quietly superseded — yet still very much alive.

/ˈwaɪərˌɡɑːrd/

n. “Small, sharp, and unapologetically modern.”

WireGuard is a next-generation virtual private network protocol designed to do one thing extremely well: create fast, secure encrypted tunnels without dragging decades of legacy complexity along for the ride. Where older VPN systems grew layered, configurable, and occasionally fragile, WireGuard arrived with a different philosophy — fewer options, fewer lines of code, and far fewer places for mistakes to hide.

At its heart, WireGuard operates at the network layer and uses state-of-the-art cryptography by default. There is no menu of outdated algorithms to choose from and no opportunity to accidentally weaken security through nostalgia. Encryption is handled using modern primitives such as ChaCha20 for confidentiality and Poly1305 for message authentication, while key exchange relies on ECDH over Curve25519. These choices are not negotiable — and that rigidity is deliberate.

Unlike OpenVPN, which builds its tunnels using TLS and can span thousands of lines of configuration and code, WireGuard is famously compact. Its reference implementation is measured in a few thousand lines total. That small size makes auditing realistic rather than aspirational, and it dramatically reduces the attack surface available to bugs, misconfigurations, and accidental foot-guns.

One of WireGuard’s most striking design decisions is its approach to identity. Each peer is identified by a static public key, much like an SSH key. There are no certificates, no usernames, and no renegotiation storms. If a packet arrives signed by a known key, it is accepted and decrypted. If not, it is silently ignored. This makes connections fast, predictable, and resilient against many classes of denial-of-service attacks.

From a performance perspective, WireGuard is lean to the point of rudeness. It avoids unnecessary handshakes, minimizes round trips, and integrates cleanly into the operating system kernel on platforms like Linux. The result is lower latency, higher throughput, and better battery life on mobile devices compared to traditional VPN solutions.

That speed is not theoretical. In real deployments, WireGuard often outperforms both IPSec and OpenVPN, particularly on constrained hardware or high-latency links. The protocol does less work because it refuses to do unnecessary work.

WireGuard also solves a subtle but important usability problem: roaming. Because peers are defined by cryptographic identity rather than IP address, clients can move freely between networks — Wi-Fi to cellular, office to coffee shop — without renegotiating sessions or dropping connections. The tunnel simply continues, adapting quietly in the background.

This elegance comes with trade-offs. WireGuard intentionally omits features that some environments expect, such as built-in authentication portals, dynamic address assignment, or legacy cipher support. Those responsibilities are pushed outward to orchestration tools and operating system networking layers. For some, this feels incomplete. For others, it feels refreshingly honest.

In practice, WireGuard is increasingly used for site-to-site links, remote access VPNs, container networking, and zero-trust architectures where simplicity and reliability matter more than backward compatibility. It pairs naturally with modern security models and fits cleanly into automated infrastructure.

WireGuard does not try to be everything. It does not negotiate. It does not apologize. It encrypts packets quickly, verifies them correctly, and moves on. In a world of bloated protocols and accidental complexity, that restraint is its quiet superpower.

/ˈoʊpən-viː-piː-ɛn/

n. “A private tunnel built out of public roads.”

OpenVPN is an open-source virtual private networking protocol and software suite designed to create secure, encrypted connections across untrusted networks. It exists to solve a simple but dangerous problem: the internet is shared, noisy, and hostile, yet people still need to move private data across it without being watched, altered, or impersonated.

At its core, OpenVPN builds an encrypted tunnel between two endpoints using standard networking ports and widely trusted cryptography. Unlike older VPN technologies that rely directly on IP-layer security like IPSec, OpenVPN operates in user space and uses TLS for key exchange and authentication. This design choice gives it flexibility, portability, and an uncanny ability to slip through restrictive firewalls that would block other VPN protocols outright.

The cryptographic backbone of OpenVPN is deliberately boring — and that is a compliment. It commonly pairs AES for encryption with hashing algorithms like SHA256 for integrity verification, and public-key systems such as RSA or ECDSA for authentication. Keys are negotiated dynamically using TLS handshakes, meaning each session has fresh secrets even if previous ones were somehow exposed.

One of OpenVPN’s defining traits is its adaptability. It can operate over UDP for speed or TCP for reliability. It can run on nearly any port, including TCP 443, which is indistinguishable from ordinary HTTPS traffic to most network filters. This makes it particularly useful in environments where VPN usage is discouraged, throttled, or outright blocked.

In practical terms, OpenVPN is the workhorse behind countless commercial VPN services and private enterprise deployments. When a remote employee connects back to a corporate network, OpenVPN can assign them a virtual IP address, route internal traffic securely, and ensure that credentials or sensitive files never travel the network in the clear. To outside observers, the traffic appears as encrypted noise — intentional, structured noise with rules.

Unlike browser-based security mechanisms such as SSL or TLS alone, which protect individual applications, OpenVPN can secure all network traffic at once. Email, file transfers, database queries, and obscure legacy protocols all benefit equally. This makes it especially attractive for older systems that cannot be easily upgraded to support modern encryption natively.

OpenVPN is also notable for what it does not do. It does not promise anonymity by default, and it does not magically erase user identity. Like all VPN technologies, its privacy guarantees depend on configuration, logging policies, and trust in the operator. A poorly configured OpenVPN server can leak metadata just as easily as any other network service.

Still, OpenVPN has earned its reputation through longevity, transparency, and relentless peer review. Its open-source nature allows independent audits, rapid vulnerability disclosure, and community-driven improvements. In a world littered with proprietary black boxes, this matters more than marketing slogans.

OpenVPN does not try to be clever. It tries to be correct. Secure tunnels, proven algorithms, predictable behavior. No illusions. Just encrypted packets doing their quiet work while the rest of the internet argues loudly around them.