Ever wonder what actually happens when you click a link? Probably not. Most people don’t think about it until something breaks and they’re staring at a loading spinner for 30 seconds.
The internet isn’t one thing. It’s a bunch of separate networks run by different companies who all agreed to pass traffic around for each other. Your data hops between them until it gets where it’s going.
Packets: Your Data in Pieces
Your computer doesn’t send requests as one chunk. It splits everything into packets, around 1,000 to 1,500 bytes each, and sends them off separately.
Each packet carries a header with addresses and a sequence number. Think of mailing a book one page per envelope. Weird way to do it, but there’s a reason: if one packet gets lost, you only resend that piece instead of starting over.
Those packets don’t even follow the same route half the time. One goes through Atlanta, another through Dallas. They reassemble at the destination like nothing happened. The receiving computer just waits until everything arrives, puts the pieces back together using those sequence numbers, and you see your webpage.
Routers Pick the Next Stop
Routers are the machines sitting at network junctions. They check each packet’s destination against their routing tables and push it toward the next hop. BGP handles the behind-the-scenes work of keeping those tables current.
Most requests pass through 15 to 20 routers before arriving. When something goes wrong, network people usually start by checking how to find proxy server address settings and running traceroutes.
The whole thing has built-in redundancy. A router fails, traffic goes around it. Sharks bit through undersea cables near Egypt back in 2013 and most users never noticed because packets just took other routes.
IP Addresses
Every device needs an address. IPv4 ones look like 192.168.1.1, but we ran out of those years ago. IPv6 uses longer strings to fix the shortage.
Your ISP gives your house one public IP. IANA handles global coordination, distributing blocks to regional bodies who hand them to providers. Strange that it works as well as it does given nobody’s really running the show.
Your home router then assigns private IPs internally. Laptop gets one, phone gets another. Outside your network, only the public address shows.
DNS Does the Translating
Nobody types 142.250.80.46 to reach Google. DNS converts domain names into IP addresses.
You enter a URL, your device pings a DNS server, gets the IP, connects. The whole thing takes milliseconds. Cloudflare’s documentation mentions DNS adds about 10% to page load times, which explains why some people bother switching to 1.1.1.1 or 8.8.8.8.
Proxies and VPNs
Regular browsing exposes your IP everywhere you go. Proxies sit in the middle, swap your address for theirs, and forward the request. Websites see the proxy, not you.
Companies run whole pools of proxies for competitor price monitoring, ad verification, SEO audits. Hard to check prices in 40 countries simultaneously without them.
VPNs do the same address-swapping but encrypt traffic too. The EFF points out that encrypted DNS plus a VPN works better than either alone.
Distance and Latency
Data through fiber optic cables moves at roughly 124 miles per millisecond. Sounds quick until you’re playing against someone 7,000 miles away and your inputs register late every single time. Physics wins, always.
CDNs help by keeping cached copies of content on servers spread globally. That video you’re streaming probably comes from a server a couple hundred miles away, not headquarters. Netflix operates thousands of cache boxes inside ISP facilities for exactly this reason. They’d rather pay for local hardware than deal with user complaints about buffering.
What’s the Point of Knowing This
Understanding routing helps when things break. Slow connection might be a routing issue, not your bandwidth. Site won’t load? Could be DNS. Some website works fine on mobile data but not WiFi? Different routes, different potential failure points.
At minimum you’ll know which part to blame instead of restarting your modem five times hoping it magically fixes itself.
Around 5 billion people use this daily. No central authority runs it. Just agreements between networks and some shared protocols holding everything together. Occasionally someone misconfigures BGP and takes down half the internet for an hour, but mostly it works.
