ftp

#ftp client commands
binary - set binary transfer type
cd - change remote working directory
lcd - change local working directory
get - recieve file
mget - get multiple files
passive - enter passive transfer mode
ls - list contents of remote directory

#Traditional ports, though they can be dynmically assigned
Port 21 - control commands
Port 20 - data transfer

#Active mode
Client initiates control session on port 21 and leaves port 20 open for the server to send data, and the server initiates the connection for port 20.
***If client is behind a firewall, or NAT, then the sever might not be able to connect to send data.

#Passive mode
Server gives teh client a port to initiate a connection to for data transfer.
***Most commonly used by browsers, ect.