how to open closed port?
Since updating to OS Sierra, Transmission (my torrent application) reports that my ports are closed (and "Pork check site is down"), so I am unable to seed. ("Randomize" doesn't achieve anything.")
How do I get an open port?
(Everything worked fine until Sierra.)
iMac (27-inch, Late 2012), OS X Yosemite (10.10.5)