If all your other devices are connected to the internet, and your computer is the only device not connected, here are a few things you can try to get the internet back up and running.

Run Apple Diagnostics or Apple Hardware Test

Most Mac computers have a built-in diagnostic program that will scan your computer for issues, including problems with Wi-Fi.

Diagnostic Program name:
Apple Diagnostics on models from 2013 and later 
Apple Hardware Test on models from 2012 with at least OS X 10.8.4.

To run Apple Diagnostics, disconnect any Ethernet cables and external DVD or hard drives, hit restart, and hold down the D key as the computer reboots. Pick a language, and then the diagnostic will launch automatically. You can launch the Apple Hardware Test in slightly the same way. The only difference is that when the screen for the test appears as your computer is restarting and you're given the prompt to choose a language, you want to press Return or the right arrow button.

Clear your DNS cache

Clearing your DNS cache could solve issues with your Wi-Fi connection. Run the Terminal app. You can find it one of two ways:

Option 1: Open Terminal in the Utilities folder 

Option 2: Search Terminal using the Spotlight function

In the Terminal app, enter the command to flush your cache. 

The command you'll type can be slightly different depending on your Mac operating system: 

Yosemite and after: sudo killall -HUP mDNSResponder 

Yosemite 10.10–10.10.3: sudo discoveryutil mdnsflushcache 

Mavericks, Mountain Lion, Lion: sudo killall -HUP mDNSResponder 

Snow Leopard: sudo dscacheutil -flushcache 

You'll be prompted to enter the administrator password for your account. Then your cache goes bye-bye—and hopefully any glitches with it.

Switch off your antivirus software

We recommend keeping antivirus software activated on your computer. However, misconfigured antivirus protections can sometimes interfere with your Wi-Fi connection. Try turning off your antivirus software or firewall to see if the internet comes back.

Make sure you have a working IP address

Step 1: Click the Apple menu in the top left-hand corner of the screen. 

Step 2: Click System Preferences > Network. 

Step 3: Click on the network connection you want (i.e., Ethernet or Wi-Fi). 

Step 4: Select Configure IPv4. Choose the option for setting up an IP address. To have the IP address generated automatically, choose Using DHCP.

Reset your network adaptor settings 

If all else fails, then it's time to reset your computer's network adapter entirely. This changes your computer's network settings back to default. It's not the most convenient option, but it can be the fix you need; it will start from scratch and erase the Wi-Fi bugs once and for all.

Keep in mind that this isn't like turning off the computer and turning it back on. In the same way that resetting your router restores that device to factory settings, restoring your network wipes out your Wi-Fi settings, bringing your home internet back to how it was when you were setting it up for the first time.

Your computer will forget your Wi-Fi network's name, passwords, VPN settings—everything. Do this only as a last resort. And make sure you save your passwords and other necessary info before doing the reset. 

Note: This is only on the computer you are doing this on, this does not affect the Nokia Gateway, your router, or other devices on your network.

Follow these steps to reset your network settings using your Apple computer:

Step 1: Click Apple menu > System Preferences > Network. 

Step 2: Click on Wi-Fi in the drop-down menu on the left of the screen.

Step 3: Hit the minus (-) button to remove it. Then add it again by clicking the plus button (+) and selecting Wi-Fi in the Interface options. 

Step 4: Hit Apply and close out of the Network settings.

Why is my Wi-Fi down? 

You may be unable to connect using Wi-Fi, but have no issues accessing the internet using an ethernet wire.  In this case, there may be an issue with your Wi-Fi router. Unplug and reboot it, check if it has up-to-date wireless settings and a valid IP address, and restore it to factory settings if necessary. 

Why isn't my Nokia Gateway connecting to the internet?

If your Nokia Gateway from Connexion isn't connecting to the internet, this most likely means it is not communicating correctly with our network. The first thing to try is to reboot the Nokia Gateway and see if everything starts working again. If this does not restore your service, please contact Connexion support for assistance.  (How to contact Customer Support, Technical Support).