On Wed, 24 Jan 2018 17:25:43 -0500, Julie Marchant wrote: > I get the impression that the whole trend of using the "www" subdomain > came from Usenet hierarchies. Is that accurate?
It's important to understand that one host might not handle all of the services associated with a domain. The "A" record (or "AAAA" for IPv6) is IP address(es) of primary host for that domain, but other records may specify that some of the services for that domain are on other hosts or addresses; for example, the MX record specifies a host for handling email. When building the World Wide Web, they didn't go through the process of adding a WWW or WEB or something record type to DNS, and just assumed that the web server for that domain would always be running on the primary host for that domain. Of course, some sysadmins didn't like that (running this weird new Web thing on their core infrastructure!? egad!). So, they'd deploy the webserver on a separate host, and name that "www.DOMAIN". Of course, the web became a killer-app of the Internet, and it became weird to think that the "main" host of a domain did something other than run a web server. Today, we have generic SRV records so that you don't have to go through the process of adding a DNS record type for new protocols (for example, XMPP uses SRV). There have been a few proposals to have HTTP use that, and fall back to A/AAAA records, but none have gone anywhere. > In any case, many websites these days don't do that anymore, and even > when they did it was never necessary. So yeah, it's inaccurate to say > that websites' URLs *should* have that prefix. Just optional fluff some > people like to use. Indeed. It's optional fluff, but fluff that is nice for a couple of reasons. The "www." prefix is nice because it means to most people "this is a thing you type in to your web browser", even if they know nothing about technology; even more-so than "http://"; or "https://"; (which also don't work as well verbally). But that's probably not so much of a concern for GNU distros ;-) The "www." prefix is also nice because it lets you use a CNAME record to manage which of your real hostnames is responsible for serving that content, as you can't use a CNAME for the root of a domain. (This is why we use www. for Parabola.) Though, some contend that this practice is just an ugly hack around DNS servers' config file syntax not having ways to define aliases that get resolved server-side, and that this should be solved by pre-processing the config file. -- Happy hacking, ~ Luke Shumaker
