IPv6 zones in URLs are a mistake

IPv6 is weird. One of the more strange parts of the standard is that every interface's link local addresses are in fe80::whatever. If you have a machine with two network interfaces, both of them will be in fe80::, so if you have a packet destined to fe80::4, how do you disambiguate it? The answer is you use IPv6 scopes/zones. The exact format of what goes into a zone is OS dependent, but on Linux it's the interface name and on Windows it's the interface ID. This lets the kernel's routing table know how to handle an address range conflict. On my tower, this would be represented like this: fe80::4%eth0 Where eth0 is the name of my tower's ethernet device. When you create a host:port bindhost, you normally separate the hostname and port with a colon. IPv6 uses colons to separate hex groups. In order to disambiguate what's the host and what's the port, you typically format the IPv6 address in square brackets, so fe80::4 on port 80 would look like this: [fe80::4]:80 And with the right…