First important thing we should mention are the restrictions. As ftp can have dangerous usages, it is restricted for Calar Alto Network. Main points to take into account are:
(a) From outside Calar Alto you cannot access any internal machine with ftp but ftp.caha.es, our anonymous ftp server.
(b) To access external ftp servers from Calar Alto computers, you must use ncftp command (see man ncftp) instead of ftp command. You have to configure ncftp to access the correct proxy server. Please, see below for this configuration.(c) Command ftp is still working within Calar Alto Network on Solaris systems. On Linux boxes you have to use sftp or scp. Anyway, on both cases we suggest to use secure connections if possible.(d) If using a browser, you have to configure it for using our ftp proxy:Proxy: derfel.caha.esPort: 3128You will use ncftp for accessing external anonymous servers. Normally, ncftp has a configuration file called ~/.ncftp/firewall The first time you use ncftp, you have to enter some information inside this file. Please, edit it and change the next entries:firewall-type=1firewall-host=derfel.caha.esAnd do not use any user or password (comment the correspondent lines). Save the file and that's all.
As mentioned above, our anonymous ftp server is called ftp.caha.esThere are two possible users for using all the features.
3.a The first user is the one everybody knows: anonymous (if you prefer, you can use word "ftp" instead of "anonymous"). You contact our ftp machine as normal:> ftp ftp.caha.es
Connected to ftp.caha.es.
220 FTP server ready.
Name (ftp.caha.es:usuario): anonymous
331 Use your email account as password.
Password:This is as usual. Once inside ftp:(a) You can see all ftp commands with 'help' or execute '? command'.
(b) Just after entering as anonymous, if you type dir you'll see nothing. Do not worry about that. The normal pub directory is still there, although you cannot see it. So, inmediately after being on the system, change to the pub directory as usual:ftp> cd pubThen you'll be into a correct place, and the dir command will show you the directories under pub.(c) When you change to one of the pub's subdirectories, then you'll see all the files you can retrieve (or other directories). To get the files you still use the normal commands 'get' or 'mget' . But also you'll see a special directory called 'incoming'. Normally, when a user is created inside ftp area, this directory is also created below the user's directory. Under that directory, anonymous user can leave (put) files, so anonymous can do:ftp> cd pub 250 OK. Current directory is /pubftp> cd edejuan250 OK. Current directory is /pub/edejuanftp> cd incoming250 OK. Current directory is /pub/edejuan/incomingftp> put calar.jpglocal: calar.jpg remote: calar.jpg227 Entering Passive Mode (150,214,222,232,178,209)50 Accepted dataconnection100% |*****************************| 948 KB 11.20 MB/s 00:00 ETA226-File successfully transferred226 0.084 seconds (measured here), 10.97 Mbytes per second970975 bytessent in 00:00 (10.93 MB/s)ftp>One important thing: anonymous user can PUT files on /pub/incoming but he cannot GET files from that directory. He can GET files from /pub/ but not from /pub/incoming3.b The second user is . If you want to use it, please, contact system group for account and password. Its purpose is to allow people at Calar Alto to put files on the ftp area, I mean, on those directories called /pub/, so other people arround the world can retrieve them. This user is special. You cannot use this account for telnet/ssh. It only allow ftp connections. So, a normal ftp session with this special user looks like:
331 User OK. Password required
230-User has group access to: 100 500
230 OK. Current directory is /
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd pub
250 OK. Current directory is /pub/edejuan
ftp> mkdir test
257 "test" : The directory was successfully created
ftp> cd test
250 OK. Current directory is /pub/edejuan/test
ftp> put calar.jpg
local: calar.jpg remote: calar.jpg
227 Entering Passive Mode (150,214,222,232,208,168)
150 Accepted data connection
100% |********************************************| 948 KB 11.20 MB/s 00:00 ETA
226-File successfully transferred
150-Accepted data connection
150 948.2 kbytes to download
100% |********************************************| 948 KB 10.98 MB/s 00:00 ETA
226-File successfully transferred
226 0.076 seconds (measured here), 12.17 Mbytes per second
970975 bytes received in 00:00 (10.96 MB/s)
In above both cases, you'll be asked for your remote computer password.
See man scp for more information.