ftp ftp/tcp: unknown service

[Ron Cornwell]

Please add more information about your problem.

[Antoanetta Naghiu]

Check /etc/services file to see if you have defined ftp and is not somehow commented out. You should have something as:
ftp 21/tcp #File Transfer Protocal
Check if inetd daemon is running (ps -ef |grep inetd).
Check if /etc/inetd.conf has as a valid line
ftp stream tcp nowait root /usr/lbin/ftpd ftpd -l -u 000 (the start line could be diferent, see man inetd.conf) and
tftp dgram udp wait root /usr/lbin/tftpf tftpd.
Hope this helps.

[Donald Branch]

if running nis check nsswitch file to see if your using nis services file or your local. if know nsswitch file put one there because I believe the default when you don't have one and your using nis is to use the nis services file.

[Jason Luginbuhl]

In addition to the previous advice of checking /etc/services and making sure that you are looking to "files" via the services line in /etc/nsswitch.conf, you also need to make sure that the remote system has inetd running. I have seen inetd spontaneously die on systems that are not patched properly. Since inetd listens for ftp/telnet requests before spawning the ftpd and telnetd daemons, if it ain't running then you won't be able to telnet or ftp into that box.