People write in with mysteries all the time. One is why their Mac (and sometimes other devices) will seemingly connect to a Wi-Fi network just fine but not be able to access the internet via that connection. They know the password and network are both correct: they have other devices, like an iPhone, connected without a problem.
The culprit is usually a firewall or VPN. Most people no longer use firewall software, even though macOS continues to offer it as an available feature in System Settings > Network. Apple’s is largely an application firewall, one that allows apps to communicate in and out, rather than a network one that can be configured to block incoming addresses, connections to certain internet ports on your computer, and other activities. (This is available from the command line in macOS, however.)
If you use a third-party firewall that blocks traffic and can’t connect to the internet after making a valid Wi-Fi connection, check its rules and configuration. You may need to disable it for a moment or enable an option that prompts you to allow a new network configuration before proceeding.
It’s more likely that you have a VPN (virtual private network) enabled for work, school, or personal protection. A VPN creates an encrypted tunnel between your device and some other point on the Internet, which may be inside a corporate or academic network’s firewall or in a data center when you’re using a VPN you pay for as a service.
The trouble isn’t the VPN but the VPN’s ability to connect. When you connect to Wi-Fi, your VPN settings may have the service try to connect with its counterpart at the other end of the tunnel. If it can’t make that connection, it can appear that you have no internet connection.
The solution is to either disable or remove the VPN. Depending on the VPN’s settings, you may be able to just flip its switch off; in some cases, you may need to disable an option that has it try to always make a VPN connection as soon as you connect to a network. VPN settings are located in Settings (iOS/iPadOS) or System Settings (macOS) at the top level if enabled or in Network. Configurations may be nested under VPN & Filters, depending on your version of the operating system.
You can remove a VPN configuration by clicking or tapping the i (info) icon to the right of its name, clicking or tapping Remove Configuration, and confirming the operation. In iOS or iPadOS, you can also go to Settings > General > VPN & Device Management, select the VPN’s profile, tap Remove Profile, and confirm.
This Mac 911 article is in response to a question submitted by Macworld reader Ken.
Ask Mac 911
We’ve compiled a list of the questions we get asked most frequently, along with answers and links to columns: read our super FAQ to see if your question is covered. If not, we’re always looking for new problems to solve! Email yours to mac911@macworld.com, including screen captures as appropriate and whether you want your full name used. Not every question will be answered; we don’t reply to emails, and we cannot provide direct troubleshooting advice.