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Advanced topics

Deeper material for engineers, network admins, and the technically curious.

15 articles

networkingsecurityadvanced

What is RPKI? BGP security explained

BGP runs the internet on trust. RPKI replaces some of that trust with cryptography, letting routers verify that a network actually owns the IP space it announces. Here's how it works and why deployment took fifteen years.

May 6, 20266 min read
dnsnetworkingadvanced

What is mDNS / Bonjour? Local network discovery explained

Your printer just appears on your network. Your AirPods reconnect automatically. Chromecast finds your TV. The reason all of that 'just works' is mDNS — multicast DNS, the silent infrastructure of local networks.

May 6, 20265 min read
networkingadvancedisp

What is BGP, and how do route hijacks happen?

BGP is how networks tell each other where to send packets. It's the routing fabric of the entire internet — and also one of its most fragile pieces. Here's how it works, why it occasionally fails spectacularly, and what's being done about it.

May 6, 20266 min read
networkingadvanced

What is an ASN? Autonomous System Numbers explained

Every IP block on the internet belongs to an Autonomous System — a network operator with its own routing policy. Here's what an ASN is, how to look one up, and why network engineers care.

May 6, 20265 min read
networkingperformanceadvanced

What is a load balancer? Plain-English guide to scaling traffic

When one server can't handle the traffic, you put a load balancer in front of many. Here's how load balancers work, what algorithms they use, and where they fit alongside CDNs and DNS.

May 6, 20265 min read
securitynetworkingadvanced

What is a DDoS attack and how does protection actually work?

DDoS attacks flood a target with so much traffic that legitimate users can't get through. Here's how attacks work in 2026, the categories of attack, and why anycast networks make protection at scale possible.

May 6, 20266 min read
networkingadvanced

TCP vs UDP: what's the difference and when does it matter?

Every internet connection uses either TCP or UDP. TCP is reliable and ordered; UDP is fast and lossy. Here's the difference, the use cases, and why modern protocols are quietly mixing both.

May 6, 20266 min read
dnsnetworkingadvanced

Reverse DNS lookup explained: what PTR records are and why they matter

A reverse DNS lookup turns an IP address back into a hostname. Here's how the PTR record system works, when it matters (a lot for email; rarely for users), and how to test your own reverse DNS.

May 6, 20265 min read
torprivacyadvanced

How does Tor work, technically?

Tor is more than 'a slower VPN.' It's a fundamentally different anonymity model — three random relays, layered encryption, and no single point of trust. Here's exactly what happens when you load a page through Tor.

May 6, 20266 min read
securitynetworkingadvanced

How HTTPS certificates actually work

Every HTTPS connection starts with a server proving who it is via a certificate signed by a trusted authority. Here's the chain of trust, why Let's Encrypt changed everything, and what 'invalid certificate' warnings actually mean.

May 6, 20267 min read
networkingperformanceadvanced

How HTTP/3 changed the web (and why you didn't notice)

HTTP/3 quietly replaced TCP with UDP and rewrote the assumptions of decades-old web infrastructure. Here's what changed, why it's faster, and why your browser is probably already using it.

May 6, 20266 min read
networkingadvancedipv4

How does NAT actually work? Network Address Translation in detail

NAT is the trick that lets dozens of devices in your home share a single public IP address. Here's exactly what NAT does to packets, the different NAT types, and why it caused decades of headaches for peer-to-peer apps.

May 6, 20266 min read
vpnnetworkingadvanced

How does a VPN work, technically?

A VPN sounds simple — 'it hides your IP' — but underneath there's encryption, tunneling protocols, key exchange, and routing changes. Here's exactly what happens when you click Connect.

May 6, 20267 min read
networkingperformanceadvanced

How CDNs work: the invisible layer that makes the web fast

Most popular sites are served by a Content Delivery Network — a global cache layer between you and the origin server. Here's what CDNs actually do, why they speed up the internet, and how the major ones differ.

May 6, 20266 min read
networkingadvanced

Anycast explained: how the same IP is in 200+ places at once

When you query 1.1.1.1, dozens of physical servers around the world could answer — and the right one always does. That trick is called anycast, and it underpins modern DNS, CDNs, and DDoS protection.

May 6, 20265 min read