How to Fix Wi-Fi Issues on Mac Running macOS Catalina or Earlier

A new OS update from Apple always creates some problems for users who own an iPhone, iPad, iPod touch or Mac. Apple repeats history in the case of iOS 12.

macOS Mojave, as it seems, is no better when it comes to teething troubles. Recently, many Mac users have raised their concerns over WiFi issues. Apart from Wi-Fi troubles, users have also ranted about issues in Microsoft Office, printing landscape-oriented docs, iTunes, and Airdrop.

Coming back to our concern of solving the issue, it’s quite easy to get rid of this problem. Just remove some old preference files and create new network settings on your Mac and Bob is your uncle!

How to Fix WiFi Issues in macOS Catalina or Earlier

Get Rid of Current Wi-Fi Preferences and Make a Fresh Start

Step #1. Create a folder on your Mac to take a backup of existing WiFi preferences.

Step #2. Assign a suitable name so that you can remember in the future. i.e. Old Wifi Preferences.

Step #3. Now switch off WiFi from the menu from the upper right corner of Mac screen.

Step #4. Click on Finder from Dock.

Step #5. Hit Command+Shift+G.

You will get Go to Folder command.

Step #6. Select the below-mentioned path:


Step #7. Hit Return.

This will take you back to Folder, from where you can select below files.


Locate Wifi Configuration Files on Mac

Step #8. Move the above files to the folder you have already created (as mentioned in the first step of this how-to). You can also delete the files.

Step #9. Now restart your Mac.

Now turn the Wi-Fi on; if this doesn’t give you any positive result, you should go for creating a new custom network.

Go for the new WiFi network creation with custom DNS

Step #1. First off, shut down all apps like Safari, Chrome, Mail, etc. that are running on Wi-Fi → Click on Apple menu → Click on System Preferences.

Click on System Preferences in Mac

Step #2. Click on the network from system preferences.

Click on Network on Mac System Preferences

Step #3. Now click on the WiFi from the list → Click on Location menu → Choose Edit Locations.

Click on Edit Location in WiFi Settings on Mac

Step #4. Now click on + sign to create a new location, type in a suitable name for the network and Click on Done button.

Add New Wi-Fi Location in Mac OS X El Capitan

Step #5. Now join the Wi-Fi network beside “Network Name” → Type in your router password.

While you are on Network screen, click on Advanced button from the lower right corner.

Step #6. Click on the TCP/IP tab → Next, click on the Renew DHCP Lease button.

Click on Renew DHCP Lease in Mac OS X El Capitan

Step #7. A warming message will popup; click on Apply.

Click on Apply to Renew DHCP Lease in Mac OS X El Capitan

Step #8. Click on DNS button on Network screen → Click on (+) Sign from the lower left corner under DNS servers → Now type in new DNS server on blank white space under DNS servers. i.e. and (Google’s DNS)

Add New DNS in Mac OS X El Capitan

Step #9. Click on Hardware button → Under Mac Address, you will see a drop-down menu next to Configure → Select Manually from the menu.

Configure Hardware in Mac OS X El Capitan

Step #10. Next, select Custom from the drop-down menu next to MTU → Type in MTU number: 1453.

Configure MTU Manually in Mac OS X El Capitan

Step #11. Click on OK → Lastly, click on the Apply button to create a new WiFi network.

After following this long procedure, your network connection should work properly. You can also check the speed to confirm whether your internet is working right or not.

Also, read some more tips to resolve Wi-Fi issues.

  • Reset the Mac SMC.
  • Restart your Mac in Safe Mode.
  • Restart again (this will discard cache).
  • Restart the WiFi router with which your Mac is connected.
  • Make sure that you are using the latest Wi-Fi router firmware.
  • Connect to 2.4 GHz network if you are on 5 GHz G network or B network.

If any of the above methods doesn’t give you a result, you should go for cleaning installation of macOS.

Fix WiFi Issue on Mac

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Jignesh Padhiyar
Jignesh Padhiyar is the co-founder of who has a keen eye for news, rumors and all the unusual stuff that happens around Apple products. During his tight schedule, Jignesh finds some moments of respite to share side-splitting contents on social media.


  1. I had an issue where the wifi hardware would just not connect anymore. I would restart and it may work. Tried all of the fixes on various sites to no avail. So, I downgraded to Yosemite – issue seemed to be the same, so I then upgraded again to El Capitan and they seemed to be no improvement. So, I disabled SIP again and it has been much more reliable since. I now ‘Switch Off’ my Mac to help preserve the reliability of my Wifi Signal.


    Macbook Pro mid 2010, 13″, 2.4ghz, 8GB, 10.11.2 El Capitan

  2. Thank you! The first part about replacing pref files didn’t help, but, interestingly, changing the MTU size did. I had trouble with wired ethernet from the day I installed El Capitan, but WiFi had been working acceptably until today. After a Comcast modem went up and down a few times, all networking on the Mac Pro was broken. Changing and applying new network settings would bring the network back for a few seconds, then the network would disappear again. I tried many, many things, including creating a new user account, booting in safe mode, etc. *Only* changing the MTU value had a lasting effect. At least it has been 15 or 20 minutes now of continuous network connectivity, which is a first for today. Sounds like Apple has a buffer overflow of some kind with the default packet size of 1500 bytes. What do you want to bet it’s an off-by-one error, and you could actually get away with 1499 bytes for the MTU? :} (Not that I’m going to try that experiment just now. I’m seriously tired of battling my Mac’s networking.)


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