Taking down my site on purpose:

If you have multiple computers, you'll quickly run into the problem of having data on one but needing it on the other. Because of this, people have been connecting them together since the beginning. However, this created a classic problem: Each network used it's own addressing scheme, wire protocol, headers, etc, etc... If you wanted to get a file between two networks, you had to find a machine that was connected to both and manually forward it. To automatically route data between networks, we had to agree on a universal numbering scheme for computers. During the 1980, people settled on the 32-bit "IPv4" address. Here's my server's address (split into bytes): 65.109.172.162 Back then, computers were massive and extremely expensive, so 32-bits was plenty: After all, there's no way there would ever be billions of computers in the world... There was enough margin to assign addresses roughly geographically and in power of 2 sized blocks. This allowed the internet to be scalable because each router doesn't have to know the exact details of every computer: When your ISPs network sees my address, it doesn't have to know that what specific computer 65.109.172.162 is, just that everything starting with 65.109 should be sent to Finland. ... but does mean that we can't even have the full 32-bits of address space. We ran out around 2011. To keep the internet working, people started hiding multiple computers behind a single address. Odds are, every single machine on your home network has to share a single IPv4 address using a rather complex "NAT" setup. ... but even this is not enough. Recently, ISPs have started putting multiple customers behind a single address. This obviously creates problems if you want to host services from home (a website, multiplayer games, etc), but is also a problem for normie activities: It's common to get punished by a website for something you didn't do. If you've ever seen a "You've been blocked" message, gotten a Captcha every time on a specific site, or simply had it mysteriously refuse to load... there's a good chance this is what's happened. Someone who had the address before you was either doing something bad — or more likely — got hacked and was used as an unwitting proxy for a criminal's traffic. Blocking by IP address is the one effective way to deal with bad actors on the internet: It's the only way to block a particular person without requiring everyone to make an account. The solution is quite simple: If we've run out of addresses that fit in 32-bits... just use longer ones. This was first standardized all the way back in 1995 with IPv6 and 128-bit addresses: four times as long as IPv4. Here's how many unique addresses that allows: 340,282,366,920,938,463,463,374,607,431,768,211,456 That's quite a bit. Here's mine: 2a01:04f9:c011:841a:0000:0000:0000:0001 These larger addresses also have a lot of other benefits: There's less need for virtual hosting, the address hierarchy can be cleaner, and it's possible put MAC addresses in a /64 block for stateless (and predictable) IP assignement. Problem solved, right? No. Despite being around for 30 years (almost as old as gopher!), most people still do not have access to an IPv6 capable network: /* HTML tags, keywords, commands */ h-n {color: #F27;} /* Values */ h-v {color: #B8F;} /* CSS selectors, attribute/varable names, file names */ h-s {color: #AEE;} /* Comments */ h-c {color: #777;} h-e {color: #F6F;} 10 Users don't have IPv6 support 20 ... so websites are forced to support (ancient) IPv4. 30 ... and users don't notice they are missing anything. 40 ... and don't complain to their ISP 50 GOTO 10 Because of this, even though the solution has existed ~forever, bad decisions from 1980 continue to make your internet connection worse and more expensive. To help break out of this cycle, I've decided to remove IPv4 support on my site. Cutting off most of my readers is a bit hash, so it'll only be disabled for one day each month: The 6th will now be IPv6 day. Any attempts to access my site over IPv4 will yield a message telling you that your network still doesn't support a 30 year old standard. If you really want to access my site during the sixth, use your phone. All major cell carriers have long since caught up with the times (because giving each device it's own address improves performance). Obviously, one website going down is just a site going down. For this to work, a lot of people have to do it. If you have a website where 97% uptime is tolerable, please consider doing this. If downtime is too much for you, how about a banner that warns about IPv4? Related: /outdated.html: The message in question. /misc/v6day/: IPv6 only link. Avoid any suprises on May 6th. https://xkcd.com/865/: The one scenario where 128 bits is not enough.