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It’s no secret Mac users are always more or less complaining about various Wi-Fi problems.

But if Apple’s support forums and the Interwebs are an indication, the level of annoyance with the networking stack in Apple’s desktop and mobile operating systems has seemingly skyrocketed following the release of iOS 8 and OS X Yosemite in the fall of last year.

Indeed, my MacBook Air running Yosemite drops Wi-Fi connection several times per day and takes about thirty seconds to re-connect to my home Wi-Fi after waking from sleep. Before Yosemite, I would be online literally as soon as I opened the lid.

Having installed El Capitan on my MacBook Air yesterday along with iOS 9 on my iPad Air, I’m happy to report that the vast majority of Wi-Fi problems plaguing users have become a thing of the past, here’s why.

Most, if not all of networking issues plaguing Yosemite and iOS 8 users can be pinpointed to Apple’s irrational decision to replace the trusty old mDNSResponder process that has handled networking on Macs for twelve years with a brand new one called discoveryd, which does the same thing.

Here’s the dreaded discoveryd process as captured in Activity Monitor on Yosemite.

OS X Yosemite Activity Monitor mDNSResponder screenshot

Long story short, the Internet is full of horror stories about bugs in discoveryd.

These issues are nowhere to be found in the old process so after realizing its stupid mistake, Apple has—thankfully—decided to switch back to mDNSResponder beginning with OS X 10.10 beta 4 a few weeks ago.

Even better, a big part of what makes iOS 9 and El Capitan great is the fact that both operating systems use the old mDNSResponder process which—even though not perfect—is very reliable and far, far less annoying than half-baked discoveryd.

If you take a closer look at Activity Monitor on El Capitan Developer Preview, as evidenced on the screenshot below, the old mDNSResponder process, not discoveryd, is now loaded by the operating system.

OS X El Capitan Activity Monitor mDNSResponder screenshot

And if you fire up Xcode developers tools and use the Instruments feature, you’ll notice that that discoveryd has been replaced with mDNSResponder on iOS 9 as well. Good riddance!

That Apple has decided to switch back to using mDNSResponder just a year following didscoveryd’s introduction is an admission of guilt if I ever saw one.

It’s still baffling to me discoveryd passed quality control.

I can only imagine that Apple’s software teams must feel ashamed having shipped such an important system feature that’s riddled with bugs, creating all sorts of issues for its users.

But I’m glad they did the right thing.

Networking-wise, as many have noted thus far, Yosemite is a nightmare to use.

That said, I’m super excited El Capitan shows none of the dreaded Wi-Fi issues I used to experience in Yosemite on a daily basis, such as WiFi disconnecting at random times, a network process using 100 percent of the CPU, non-responsive DNS server or invalid DNS configuration, perpetual renaming of network devices (Apple TV becomes Apple TV (2), Apple TV (3) and so forth), to name but a few.

I’m sure you’ve experienced some of these issues yourself, no?

  • Sims

    Is there a way to see real usage time in Activity Monitor or in OS X?

    • Yez I. Am

      I thought that’s all it provides? At least mine is updating constantly based on what appears to be real time usage data.

      • Sims

        The ‘time on battery’ in Activity Monitor includes all time even when you close the lid and are not using the macbook it carries on counting. I wanna see usage time of only when I’m actually using the macbook if that’s possible

      • Yez I. Am

        I understand now, but can’t help you. Good luck.

    • Mr_Coldharbour

      Open up Terminal (found in Utilities folder) and type in “uptime” (without the quotes of course) and press ENTER/RETURN. There you should see how many hours your Mac has been running.

    • Tigeraptor5

      Open Activity Monitor. Go to View>Update Frequency>Very Often (1 sec)

  • yzjustdatguy

    I caught drift of the discoveryd process on my iPhone back when I was jail broken. 40% of my battery was consumed by it. Now I realize that it’s what makes my iPhone reconnect to my home wifi all the time.

  • Gerry

    What I want them to fix is the Proxy issue for 3rd party applications in ios. 95% percent of my apps won’t connect with my University’s wifi

  • mrgerbik

    I bet discoveryd is full of sniffing algorithims & user data mining functions (data is not for resale of course!) for Apple to “improve the iOS/OSX experience”

    • Yez I. Am

      Careful, your paranoia is starting to peek through.

    • That would be pure assumption.

      The reason why Apple moved to discoveryd is so that iOS 8 and Yosemite could accommodate the new wireless features such as Continuity and Handoff, it has nothing to do with data mining.

      • “it has nothing to do with data mining.”

        Really? ‘Cause that’s a logical way of creating targeted advertising for iAds…just like Google.

      • apriliars0000

        Im going to france tomorrow, overtime I have opened youtube in the last week the intro ad is about tours of Paris and cheap train tickets and hotels. I have never seen that kind of targeting in iAd. Not saying that they don’t do it, but googles version is just creepy

      • Maybe you have “limit ad tracking” enabled?

      • Discoveryd isn’t related to analysing browsing habits, iAd has its own framework for that. I’m not saying that Apple doesn’t mine data, I’m just saying that they do it through a separate process.

      • Kk, thanks for the information.

  • Yez I. Am

    Your story hit home on a couple issues, 100% CPU power and Apple TV numbering…never noticed the iNet drops outs, but none the less, now I’m really looking forward to the OS Update.

  • Glad to see this is being fixed. I don’t know why they changed something that worked and then shoved it out to users without making sure it actually worked. iOS 8 and Yosemite really were rushed out to users. Glad to see Apple do a Snow Leopard year again.

  • Preben Faarkrog Hansen

    YES!!! can’t seem to get my new/old Extreme 4gen. to work right, hope El Capitan does the trick.

  • Jason Dennery

    Am I the only person who has never had any of these wifi issues?

    My wifi has always worked fine on my MacBook Air and iPhone 6.

  • Bugs Bunnay

    We shall see about that!

  • Jerry Suppan

    Yes, I also experienced repeated renaming of my local network computers almost being driven to a point of madness trying to reset computer names back to my original naming scheme. And, with iPhone 6+ (and previous 5) I don’t know if discoveryd is related but to this day, today, I am still getting, ‘iPhone could not sync because it is disconnected’, or something to that effect. I presume this matter is also discoveryd-related? Once in awhile I can sync and can perform a backup, but after repeat attempts to do so.

    Anyway, thanks for the heads up on this improvement. Apple should not even wait for release of El Capitan. They should take action NOW on their existing 10.8.4 (or 10.8.5) to the benefit of users now.

  • enderandpeter

    This article especially saddens me because ever since upgrading from Yosemite to El Capitan, networking is the only thing that does not work. I can connect to a wireless or wired device just fine, but visiting anywhere in a browser says “Unable to connect” and when I try to ping any network address with the exception of loopback addresses, the command says “Operation not permitted”. Why the heck am I the only one experiencing this?

    • enderandpeter

      Alright, I’m back on the Internet. The problem was the third party program Norton Firewall which wasn’t working right after the upgrade. Uninstalling it let me connect to the Internet again. I hope it works as it should after reinstalling.

    • CraigG

      You’re not the only one. I had no problems with wireless under Yosemite. Nada. Haven’t been able to connect at all since installing the public Beta of El Capitan.

  • mikebrowndesign

    Big surprise: Airport doesn’t work in El Capitan and due to Apple’s new and well-deserved reputation for releasing junk software, I don’t expect it to ever work.

    • same here: need to reset Airport on El Capitan all the time. WIFI is totally broken in OSX.