As Bloomberg News put it today in a story about Alpha, some mines must die for others to live. And some companies will also die. CONSOL Energy Inc. (NYSE: CNX) is the largest coal producer by market cap, but its survival plan is based on becoming a natural gas producer.So far that has been only a partial success because natural gas prices are so low.nd some companies will also die. CONSOL Energy Inc. (NYSE: CNX) is the largest coal producer by market cap, but its survival plan is based on becoming a natural gas producer. So far that has been only a partial success because natural gas prices are so low.
From the server-side firewall's standpoint, to support passive mode FTP the following communication channels need to be opened: 1  FTP server's port 21 from anywhere (Client initiates connection)  FTP server's port 21 to ports > 1023 (Server responds to client's control port)
FTP is a TCP based service exclusively. There is no UDP component to FTP. FTP is an unusual service in that it utilizes two ports, a 'data' port and a 'command' port (also known as the control port). Traditionally these are port 21 for the command port and port 20 for the data port. The confusion begins however, when we find that depending on the mode, the data port is not always on port 20.