Nicht nur Port 21 ..
ftp-data 20/tcp File Transfer [Default Data]
ftp-data 20/udp File Transfer [Default Data]
# Jon Postel <postel&isi.edu>
ftp-data 20/sctp FTP
# IETF TSVWG
# Randall Stewart <rrs&lakerest.net>
# [RFC4960]
ftp 21/tcp File Transfer [Control]
ftp 21/udp File Transfer [Control]
# Jon Postel <postel&isi.edu>
ftp 21/sctp FTP
# IETF TSVWG
# Randall Stewart <rrs&lakerest.net>
# [RFC4960]