Image: Jamie

DNS is known as the address book of the Internet: when you want to visit a website you will know its hostname, such as In reality the website is hosted on a webserver which can be reached at a specific IP address. So how to find that address? Simple, you ask a DNS server!

In recent years, the use of DNS has become more and more of a privacy headache. In the old days, most of our communication over the Internet was not encrypted. That made it relatively easy for hackers to eavesdrop. These days, more and more websites support HTTPS: encrypting the traffic makes it impossible (or at least much harder) to listen in. But before we can reach that website, we’ll need to know its IP address and for that we’ll first need to perform – indeed – an unencrypted DNS query.

DNS traffic is typically still unencrypted and that’s where our troubles begin: for each website we visit, we’ll send a request over the Internet, asking DNS for the IP address for that hostname. This means that anyone monitoring our DNS traffic will get an easy listing of all the websites we’re visiting. To that end, it’s in fact much easier for a hacker to just focus on our DNS traffic, instead of trying to analyse every single bit of data we transmit. And it’s not just hackers we should worry about, but also our own Internet Service Providers keeping track of us. All of this was not lost on goverments trying to censor the Internet either: a simple way to block access to unwanted sites is to just block the DNS requests for those hostnames.

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Image: Cloudflare

When you visit a webpage, send out an e-mail or watch a funny cat video, how does that particular piece of data find its way from one end of the Internet to the other? You may be aware that the Internet is a collection of many smaller networks, connected to each other using routers. When a router recieves a packet of information, it will check the destination address and then forward it to the next router along the way. That router repeats the process, and so on, until the final destination is reached. So, how do routers know in what direction they should be forwarding these packets? The answer is that they use routing protocols to share information with one another. Suppose that router A knows of a way to reach a certain destination. It will communicate this route to other routers. On receiving this information, router B may answer: sure, you may know of a way to reach that destination, but I know this shorter route!

The Border Gateway Protocol

To connect various different networks together, we really all need to speak the same language. The routing protocol that thus forms the backbone of the Intenet is BGP, the Border Gateway Protocol. Like many of the fundamental protocols that make the Internet work, it was not designed with much focus on security. Routers will simply accept the updates they receive from other routers, without validating the authenticity. And this is, in fact, a big problem!

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Image: Capcom

For some online applications, network performance is critical. Any online gamer will agree, and timing is especially critical for online fighting games: a few milliseconds can literally make the difference between a hit and a miss.

Most readers will be aware that most applications send data over the Internet using the TCP transport protocol, sacrificing a bit of speed for reliability, or could also opt to use UDP for maximum performance, while accepting some data might never arrive. Whatever option you go with, you’ll still have to deal with unstable networks: some data might arrive quickly, while a little while later the network becomes more busy, slowing down the communication. For applications that are so dependent on timing, neither TCP nor UDP by itself is a good enough solution.

It turns out that there’s a lot more an application can do to deal with fluctuating network latency. Prepare to enter the world of Netcode, where specific code is added to the game itself to deal with this challenge.

In general there are two approaches: delay based, which is basically waiting long enough so that all data will hopefully arrive in time, or rollback, which is to just move forward in anticipation of what’s most likely to happen, and correct for any mistakes later when and if different information is received.

There’s a lot more to say about this topic. If you’re interested, I would love to refer you to this great in-depth article on

HTTPIf there’s one protocol that made the Internet as popular as it is today, it has to be HTTP. The protocol which, as you surely know, is used to browse the web, is getting an update!  Actually, there aren’t really a lot of exciting things I can tell you about HTTP version 3, but it is going to make browsing the web a little bit faster by using QUIC as the underlying transport protocol, instead of good old TCP.

While still a draft standard, big players like CloudFlare, Firefox and of course Google Chrome are offering support, so we can expect HTTP/3 to take off. Thanks to the people at Google that work tirelessly to make our Internet that much faster.

Birthday Balloons
Image: Morgan Lane on Unsplash

The World Wide Web is celebrating its birthday.  Thirty years ago, at CERN, Tim Berners-Lee first proposed an information system that would be able to link documents on different servers together using hypertext. For many people, the Internet and WWW pretty much mean the same thing, but there was in fact an Internet before the Web: people would send e-mails, discuss in newsgroups, read documents using Gopher or search FTP servers using Archie. However, it’s fair to say that without the Web, the Internet would never have grown into the force it is today.

The Web has brought us many good things, like e-commerce, social media and funny cat videos, but recently we’re beginning to see more of a dark side too: more and more of our life is being controlled by a few giant online corporations, we’re reading fake news, our privacy is at risk and hackers are after us. So, what can we expect for the next few years?

Tim Berners-Lee actually has some great ideas on that, as he explains in the Guardian: “The web is for everyone,” he says, “and collectively we hold the power to change it. It won’t be easy. But if we dream a little and work a lot, we can get the web we want.”

The Internet: from a decentral beginning…

From its earliest days, the Internet was designed as a decentralised network: instead of requiring all communication to go through one central piece of hardware, the Internet allowed all kinds of networks and computers to connect to each other as and when they saw fit. More importantly, the Internet was envisioned as a tool for humans to connect, work together and share information over long distances. People were even seeing this new network as a force of liberation, a carrier of free speech. Because of its decentral nature, no one organisation would be able to control it and governments would no longer be able to suppress information.

…into the hands of companies and governments

So, what happened? (Apart from the fact that we seem to be more interested in sharing funny cat videos than in exchanging grand ideas…) Despite its decentral nature. some hosts on the Internet are more equal than others. Most popular network applications are based on the client-server model. We, the clients, contact a server to request a service: please show me this website, or please send out this mail for me. At first that didn’t seem much of a problem, since anyone could (and still can) set up a server if they desire.

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