MacBook Pro connecting to Wi-Fi network but not to Internet

[desertman]

A friend of mine is telling me a strange story.

She owns a store and sometimes goes with her MacBook to the store. She had a MacBook Pro 2016 and no problem with Wi-Fi and Internet in the store (and in her house) with that old computer.

Now she has a MacBook Pro 2020 which is working perfectly fine in her house. However, when she take the new MacBook to the store the computer does connect to the Wi-Fi network - but has no Internet access. I told her to delete the store network from the system preferences, restart the computer, and connect to the same network again as a "new" network connection. She did that and has still no Internet access with the new computer in the store.

I don't know what to make of this. Does anybody here have an idea what could have happened here and how to fix it?

Thanks - desertman

 

[Honza1]

That is difficult to say from the description, but I had recently weird thing happen which caused similar issue. For some reason when I connected to my work wifi network, it set its DNS servers in networking configuration. And these did not get reset when I came home. These work DNS servers are not accessible from home and, as result, my Mac could not get on internet, even though local wifi connection and home connections were fine. The solution was to remove these DNS servers and then wifi network at home set its default (router or defined public DNS) as DNS server and all worked fine.
No idea if this is her problem... To check: Preferences, Network, Select wifi (should be the one used), Click the lock to make changes - you cannot make any changes without unlocking this, Advanced, DNS, DSN servers. Should be either router IP number of some sensible public DNS serves (e.g., 1.1.1.1, 8.8.8.8) but if it is something not sensible, just delete. It will get repopulated by network default.
In my case it never repeated itself.
Good luck.

 

[matram]

The way I approach this is to do a ”ping” to my local gateway, e.g. 192.168.0.1 and then to a public adress like 8.8.8.8. If that works it is generally the DNS. @Honza1 has given you good advice on that.

You can use the ”dig” command in terminal to check if DNS is working. Used with a url like google.com it will tell you which DNS server it is asking for a translation and what the response is. If DNS is not working you will see no response.