Alain M. Lafon

Ever since upgrading to OS X Yosemite (currently version 10.10.1 (14B25)), I experienced networking issues. Sometimes some ports were closed, meaning that various services did not work as expected (Mail, Evernote, etc). Not only that, ports could sometimes also be inaccessible on my local machine which is tough when you’re trying to develop web applications on that machine. And yeah, I truly mean ‘sometimes’. Other times it would just work well. The one work-around that I found was to switch the WiFi spot frequently which made ports accessible on remote machines as well as my local one which didn’t seem to make any sense.

I figured it must have been some kind of firewall and dug around there. OS X has shipped several firewalls over the last decade and I had a look into every single one of them. But nothing helped. On a random hunch, I went to my WiFi Settings and toggled the option “Auto Proxy Discovery” – and off went the bad spell that was on my machine. I can finally access all ports locally and externally. Who would’ve figured…