After upgrading, restoring from backup, or otherwise heavily modifying your Mac’s software setup, you might run into an issue with your system not being able to connect or maintain a connection with your Wi-Fi network. This may have you regularly turning Wi-Fi off and then back on, or selecting your Wi-Fi network to hopefully re-establish a connection, only to have the system show an error and drop the connection again.
Unfortunately this issue can be random in nature, where at times it will connect just fine, but then after a while it may disconnect once, or at other times it may never establish a connection. If this is happening to you, then there are several things you can try to hopefully fix the situation.
Your Router
1. Restart your Router
While you might suspect your Mac is the problem, try turning off your router and unplugging it for about 10 seconds, and then plug it back in. This often can kick your router into accepting your Mac’s connection attempt.
You can use your router’s configuration interface, like this one, to turn off security features and adjust radio settings.
2. Reset and update your router
Use your router’s configuration utility to reset it to factory defaults, and then set it up again. In addition, be sure to check for and apply any firmware updates that may be available for the router.
3. Turn off security features
Granted security features in your router are there to help protect your network; however, they can sometimes interfere with network activity. These features can include WPA encryption (TKIP or AES), and your router’s firewall. Since these services are meant to protect your connection, only turn them off temporarily to test whether or not they are contributing to your problem.
Often routers are dual-band, meaning they will operate at 2.4GHz and 5GHz to support more wireless protocols (e.g., 802.11 b, g, n, and ac). Along with dual radios, each band will support different channels and have different bandwidth settings. Try turning on only one radio at a time, and also try changing your router’s channel and speed. Unfortunately you might have to attempt several combinations of settings, but may find one that agrees with your network environment better.
Your Mac
1. Create a New Location
Click the plus symbol to create a new network configuration that you can set up from scratch.
On your Mac, your entire network configuration is called a Location, and contains the collection of physical and virtual connections you have set up for your system. By creating a new location, you will in effect create a new network configuration to work with. To do this, go to the Network system preferences and choose “Edit Locations” from the Location menu at the top of the window. Then click the plus button to create a new location (call it whatever you like). Close the new location window, and you should see a basic set of physical network connections you can configure, including Wi-Fi. Select the Wi-Fi connection and then choose your network from the Network Name menu to connect.
2. Remove Network Configuration
OS X Stores your network configuration files in the Macintosh HD > Library > Preferences > SystemConfiguration folder. Remove the following files from this folder, followed by restarting your Mac, to clear your network configuration. When your Mac starts up and you configure your network again, these files will be recreated:
- com.apple.airport.preferences.plist
- com.apple.eapolclient.plist
- com.apple.IPConfiguration.control.plist
- com.apple.nat.plist
- com.apple.network.eapolclient.configuration.plist
- com.apple.wifi.message-tracer.plist
- NetworkInterfaces.plist
- preferences.plist
3. Configure IPv6 to “Link-local only”
Set up IPv6 manually to have no connection, to avoid any configuration problems with this protocol, especially for older routers.
OS X supports both IPv4 and the newer IPv6 protocols; however, in most private networks IPv6 is not needed. In addition, in some instances your Mac might repeatedly set up and clear the IPv6 configuration, showing it is not properly establishing this connection with your router. To turn off IPv6, go to the Network system preferences and select your Wi-Fi connection. Then click Advanced and in the TCP/IP tab, choose “Link-local only” from the Configure IPv6 menu, or choose Manually and then enter two colons “::” as the IPv6 address.
4. Turn off network enhancers
If you have any security software, DNS encryption routines, or other enhancement software for your network connection, then turn them off or uninstall them. You might also see if there are any updates available that allow the software to run better in your version of OS X.
5. Disable Bluetooth
While Bluetooth is required for some hardware connections (e.g., keyboards and mice), if you do not use Bluetooth then consider disabling it. In many Mac systems, the Wi-Fi and Bluetooth radios are on the same hardware module and may interfere with each other, and at times in troubleshooting many people will find by turning off one you will see the other begin to work properly.
6. Reset hardware variables
Your Mac has a couple of hardware-based settings that enhance how hardware components are managed, such as what happens when your Mac’s lid is closed, and whether or not the system will maintain some services when in sleep mode, among many others. The first of these is the PRAM, which can be reset by restarting your Mac and then holding down the Option-Command-P-R keys immediately when you hear the boot chimes. Hold these until the system restarts and sounds the boot chimes again, followed by releasing them to allow it to boot normally.
The second hardware settings is your Mac’s SMC (system management controller). Resetting this will be slightly different for each Mac model, but essentially involves shutting down your system and then holding a combination of keys for a few seconds. See here fore more information on how to reset your Mac’s SMC.
6. Perform a clean reinstall
Granted a blind recommendation to reinstall OS X is a blanket approach to solving problems, but sometimes odd configuration problems may build that prevent your system from working as expected after an upgrade. While you can reinstall OS X over your current installation to preserve all of your settings, it is these settings that are part of the problem, so consider performing a clean reinstall.
Before you do a clean install, be sure you have all the installers for third-party software available, and also have a full and current backup of your Mac, so you can restore your system if needed, and migrate your data after the installation:
- Reboot your Mac and hold Command-R at the boot chimes to boot into Recovery Mode
- Open Disk Utility and select your boot drive.
- Use the Erase tab to format your hard drive.
- Quit Disk Utility
- Select the option to install OS X
- Follow the on-screen instructions to complete the installation
- When prompted, use your backup as a source to migrate your user data and applications to the new installation.
When complete, you should be able to log in and load your system with all of your prior software and data. You will have to set up some system services again, and perhaps reinstall some third-party software packages, but hopefully this will have cleared the configuration problems with your Wi-Fi connection.
I am watching these losses of the internet connection in Yosemite on a per-app basis, often after waking my MBP from sleep. The last occurrence: iPhoto was open for a while in the background. After waking up the Mac, iPhoto has lost the internet connection and nor can add Geotags neither can display my Photo Stream. Safari and Mail kept their internet connections open.
I don’t know if anyone else has had this happen after upgrading to Yosemite, my Harmony Home Control has been dropping off line and then trying to connect to my Airport Express. It would work for a while and drop again. I ran my AirPort Utility on my iPad and found I had an issue with the Apple ID associated with the device. I corrected this and things seem to be working again.
These problems are not confined to WiFi-I had similar problems with an enterprise Ethernet where it would not even do a DHCP even though it was “connected”. Creating a new location fixed the problem
Such a timely piece…. I recently began to experience an issue whereby my 2012 iMac would lose connection to either the wi-fi or Internet. It was difficult to isolate which was exactly the problem as sometimes the computer appeared connected to at least the wi-fi, while other times it didn’t.
Resetting and everything else of the wi-fi did nothing. Brand new modem too.
And weirder still, while the iMac had this connectivity issue, no other as yet known device in the house experienced this issue. Not my iPhone. Not my iPad. Not my wife’s iPad or Android phone. Not my daughter’s cell phone or Asus laptop. Just my iMac.
I pulled out my older 24-inch iMac, booted it up, updated to Mavericks, etc. and slowly, over the course of a few days found it too experienced the same issue.
Then I pulled out my little used MacBook Pro. Updated to Mavericks, etc. and what happened? Same thing. Poor to non-existent wi-fi and/or internet connectivity.
I spoke at length to Apple tech support and have come to the conclusion the problem is Mavericks. It’s the only common denominator amongst all the failures. But I have no idea (and nor does Apple) as to why this problem has suddenly developed. It wasn’t tied to the last update to Mavericks… at least it didn’t appear to be time-wise.
The only solution was to move the wi-fi to a closer location, which seems to have solved the problem (at least for the past three weeks), but it really has been a total mystery.
Excellent troubleshooting article… and timely.
Following the IPv6 advice, all my three network locations diasppeared and I am not allowed to add a new one. Network totally gone.