Noticed your iPhone and Mac’s Wi-Fi weren’t so good over the last year? You’re not alone, and Apple is finally fixing it, albeit quietly.
If you’re wondering exactly what happened, there are a few moving parts. First, you need to understand what the Domain Name System (DNS) does.
Each computer on the internet has an IP address, which is like where it can be found on a street. Domain names for websites, like thenextweb.com, have an attached IP address that locates these computers. Think of a domain name as a human-readable way to get to the right IP address.
DNS servers, like the ones Google or your internet provider offers, keep a directly of domain names and their IP addresses.
When you type thenextweb.com into your Web browser, your computer requests the address from a DNS server, then takes you to the right page. It all happens without your knowledge — at least, when it works.
For the better part of twelve years, Apple used a single piece of software called “mDNSResponder” to manage much of your Mac’s networking, including this lookup process. In general, it worked flawlessly.
The problems with discoveryd have been vast and unpredictable. You’ve probably run into at least one: duplicate computer names, random crashes, slow page loading, slow reconnection after sleep — the list goes on.
Apple tried on three occasions to patch out the problems, but the complaints continued to flow in. When a beta build of OS X hit 10.10.4 in May, discoveryd suddenly vanished after months with no fix.
At first, many wondered if it was an accident, but mDNSResponder had miraculously returned and has stuck around in the latest beta builds.