Secure Shell (SSH) is a replacement for older methods of accessing
remote computers. Protocols such as telnet, FTP and rlogin are
considered to be insecure and are no longer supported on the CDS
When an X-Windows server is started on your workstation, SSH can also
be used to send associated data traffic in a secure manner (X11
You may need to use X11 forwarding to get data through your local
You also need X-Windows to use programs such as PeakQuest, ConQuest,
SSH for Unix/Linux and the Mac
All UNIX/Linux and Mac systems (running OSX) should already have SSH
installed and support the ssh command.
You will be able to access the CDS by opening a terminal window (for
Macs from Applications:Utilities). Type "ssh -X email@example.com",
where cxxx is your CDS ID.
The "-X" option is used to allow X11 forwarding.
If you encounter problems try [e.g. Mac OX 10.4 (Tiger)] you may need
to use "-Y" in place of "-X" in the above command.
The sftp is used for secure transfer of files (SFTP) between a
local and a remote computer. Use of the less secure FTP
protocol is no longer supported on CDS servers.
SSH for the Windows PC
- PuTTY - details and downloads are
available via the official PuTTY
all you need is putty.exe
To set up PuTTY and configure it for X-windows see the section lower down
- Open Text Exceed (previously Hummingbird Exceed).
Recent versions add the option for X11 forwarding.
Available to HEI sites as a CHEST
WinSCP is a freeware SCP (Secure CoPy) client
for most of the Windows family of operating systems using the SSH
Its main function to allow secure transfer of files (SFTP) between a
local and a remote computer (use of the less secure FTP protocol is no
longer supported on CDS servers).
To get further details and download the program itself access the
for a link to the site and tips on set up and use.
SSH for UNIX/Linux
These operating systems should already be able to login securely via
If not, then have a look at the OpenSSH
Double click putty.exe to open up a PuTTY Configuration window.
Highlight the Sessions menu (if not presented at start-up) and type in the Host name (cds.dl.ac.uk) and click the radio button for SSH.
You could also add a Saved Session name such as CDS.
Highlight the SSH menu option (under Connections) and choose 2 as the Preferred SSH protocol version
[You may want to go back to Session and save it at this point]
Click on the Open button to start the secure telnet session.
Setting up X11 forwarding when using PuTTY
Click the box to Enable X11 forwarding
(In older versions up to Version 0.57 this is under the Tunnels menu option)
|To test that you can get an X-Window, start an X server |
(see our related
for further details) then type xlogo.
You should see a small box similar to the one to the right
Go back to Session, give the session a name and
save it. Next time you open PuTTY just
Load your saved session.