I was listening to the MacGeekGab today, and one of the co-hosts, Adam Christianson, mentioned the situation where, for whatever reason, some software switches in the OS or app settings flip, as in what was on goes off, or vice versa, or a different option is selected, without the owner or admin knowing.
By accident, I discovered this happened to me recently. I was troubleshooting some network issues and was looking in settings. And then I saw it. On both my MacBookPro and Mac Mini, my Firewall was turned off. For ‘eternity’, I assumed it was on. I was quite startled. I think I last turned it on at least a decade ago and had assumed it remained on during migrations. Perhaps not.
My other thought was that over the years, I have installed many things that manipulate my network settings, and perhaps one or more of these may have turned my firewall(s) off. I currently run Tailscale, Nord VPN and AdGuard, all of which manipulate my network settings. I’m not blaming these apps and services. I mention them as examples of apps that manipulate networking.
I don’t know whether it was a migration or an app where the setting changed from what I was once quite pedantic about. I’ve now created a recurring reminder to check every three months, so I don’t get caught.
Apple has a Support Article as well as a Mac User Guide page on the firewall. Other Apple OS don’t have a similar setting as the firewall is built into the software by reducing exposure to potential vulnerabilities. On a Mac, access the firewall by searching “Firewall” in the search box in settings.
29 September 2026