Apple

How to troubleshoot Wi-Fi issues in OS X Yosemite

Having trouble keeping your Mac connected to the internet? Here are some tips to keep your Wi-Fi running properly in OS X Yosemite.

Image: Apple

Updating to a new version of an OS can sometimes present frustrating problems for the end user. Unfortunately, many Mac users who upgrade to OS X Yosemite have been running into problems with Wi-Fi connectivity.

Apple is a company that clearly values wireless connectivity, both for the freedom it enables in computing and the aesthetic it creates around devices. We see this predominantly in the movement the company has made toward wireless-only devices with no physical ports provided exclusively for internet connectivity.

Problems connecting to the internet can kill your productivity. However, there are a few steps you can take to remedy the issue. As with any troubleshooting process, you want to start by isolating the problem.

Isolate the problem

The big issue around Wi-Fi problems, in general, is the number of steps and devices involved in creating and sustaining a connection. First, you'll want to establish where the problem is originating. Begin by checking another device — does your smartphone or game system have trouble connecting as well?

If none of your devices are able to connect, it might be safe to assume your problem stems from your wireless router. Try resetting the router and see if that solves the issue. However, if all devices except your Mac are able to connect to Wi-Fi, you'll want to begin working on the problem relative to your machine.

Start with the basics

The first step should always be to turn the Wi-Fi off and turn it back on again. For some reason, this is the magic fix for many technology issues. Wi-Fi is no exception. Click on the Wi-Fi symbol at the top right of your menu bar. Once clicked, one of the top options will be "Turn Wi-Fi Off." Click that to turn the Wi-Fi off, and then click the new option that appears in its place, "Turn W-Fi On," to re-enable wireless.

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The next step in the troubleshooting process would be to remove the network you are trying to access and re-add it. Start by clicking the "System Preferences" icon in your dock. Once within system preferences, you'll want to click on the "Network" icon.

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Within the network setting, you'll then want to click "Advanced..." in the bottom right hand side of the widow.

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In the advanced settings window, highlight the name of the network in question by clicking on it, and then click the minus symbol to remove that network. After you remove the network, you need to click "Ok" in the bottom right of the window for the changes to take effect.

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The next step will be to re-add the network. Click on the Wi-Fi symbol on your menu bar again and select the name of your network from the options that are presented. In the next window, input your login credentials to re-add the network. If this doesn't immediately take effect, try rebooting your machine and then give it a shot.

You can also try adding a new network location. In the Network tab, click the location drop down menu at the top of the window and select "Edit Locations." Click the "+" symbol and name the location whatever you like. Once named, click the "Done" button at the bottom of the window.

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Once you have added the new location, you can join your network of choice and you should be good to go. This will separate your network settings so you can have special configurations at work and home without affecting your connection. If you're especially confident with this kind of thing, you can set up a custom DNS as well, which could speed up your connection.

The last basic step you can take is to reset your machine's System Management Controller (SMC). You can find that process here.

Try advanced techniques

If you're able to isolate the Wi-Fi problem to your machine, and none of the basic tips seemed to help, you can take some drastic measures.

Disclaimer: Understand that if you follow the instructions in this article, you do so at your own risk. Neither TechRepublic nor any of its representatives can be held responsible for damage or loss of data.

The first advanced option you can try is to unload and then reload discoveryd using the Terminal. The mDNSResponder was recently repealed by the discoveryd daemon (disk and execution monitor), which handles some networking service requests.

Begin by opening "Terminal," Apple's line command system application. You can find Terminal by opening Finder and clicking "Applications." Once in Applications, click on a folder labeled "Utilities," and then double-click on "Terminal."

Or, use spotlight by holding the Command key and hitting the spacebar to open a search bar in the top right of you screen. Type "terminal" in the search bar and click on the Terminal application in the search results.

Once the Terminal window is open, enter the following command and hit enter.

sudo launchctl unload -w

/System/Library/LaunchDaemons/com.apple.discoveryd.plist

Enter your administrator password if you are prompted. This command will unload discoveryd. Now, to reload it, enter the following command and hit enter.

sudo launchctl load -w

/System/Library/LaunchDaemons/com.apple.discoveryd.plist

You may need to close and relaunch connected applications for this to take effect. If you still have no luck, you can try removing network configuration and preference files. Start by turning Wi-Fi off in the menu bar and opening the Finder window.

To open a search for a folder within Finder, hold the Command key, the Shift key, and the G key. When the search bar opens, enter the following phrase to get to the correct folder.

/Library/Preferences/SystemConfiguration/

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Once in the folder, you need to find the following files and either delete them, or copy them into a backup folder somewhere else on your machine, or onto a removable drive. The main thing is making sure they are moved out of the system configuration folder.

com.apple.airport.preferences.plist


com.apple.network.identification.plist

com.apple.wifi.message-tracer.plist


NetworkInterfaces.plist


preferences.plist

After you have taken care of these files, reboot your machine and turn Wi-Fi back on from the menu bar. Your computer will then recreate these files which could solve some Wi-Fi problems.

If you are having trouble with specific websites, try flushing your DNS cache through terminal.

Hopefully this will solve your Wi-Fi problems and get you back online.

Also see

About Conner Forrest

Conner Forrest is a Senior Editor for TechRepublic. He covers enterprise technology and is interested in the convergence of tech and culture.

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