Due to the security problems inherent in any University network, the
clusters on the grid are accessible by secure shell ONLY. This avoids
the thrice weekly downtime to remove the rootkits installed via telnet,
rlogin, or FTP. As a result, you'll need a secure client to get
access.
From any UNIX or similar type box, this should be no problem, clients
for ssh and scp should be installed. These work
exactly like the more familiar rsh and rcp commands.
The basics:
ssh machinename
or
ssh username@machinename
scp machinename:
or
scp username@machinename:
Ssh provides a shell from your machine, and also forwards any X traffic
(graphics or other windows) through a secure connection, encrypting your
password and all the information in the session, protecting you from
"sniffers" that listen to public network wires (which means all of them,
all of the time; if you don't believe me, use telnet for awhile, and
I'll send you the USENET news article containing your password...)
Scp uses ssh to copy files between machines. You can use it like FTP,
to move one or many files, or whole directories. However, when moving
a lot of files using wildcards, you need to be a bit careful.
When you type a command like cp *.c /tmp , your shell (or
command interpreter) helpfully expands the "*.c" for you BEFORE passing
it to the copy command. If you wish to give scp a wildcard
to be expanded on the remote machine, you need to prevent the
shell from doing this. This can be achieved simply by putting the
argument containing the machine name and filename(s) inside quotes, as
in the examples below:
scp "dstanzi@guanine:output/*.dat" ./output
scp output/*.dat guanine:/tmp/output/
For Windows Users:
If instead of a computer you are using a Windows box to access the
grid, you will need to download and install your own ssh/scp
clients. The links below provide access to some of the simplest ones
to install and use. I recommend the "putty" ssh client as the
easiest solution:
- Putty has become the standard for ssh connections
for Windows users. You should go to
the Putty
homepage and get current versions of the software. In addition
to the program below (which implements ssh , which will
provide you a terminal connection, they have an scp client
and a development version of psftp , an scp client
that looks and works like FTP.
- The following software are the current versions
as of September 5, 2000. If you want newer
versions then search the web for them.
-
Putty (putty.exe)
- TeraTerm (tterm23.zip) and SSH extension (ttssh151.zip)
- A number of windows graphical FTP clients now support
tunneling through a secure connection. I am compiling a
list of these, and will have it here soon.
If you are using one of the command line file transfer clients,
read the instructions for using wildcard characters to transfer
multiple files in the UNIX section above.