ssh, sftp, scp usage notes

This gives basic examples of ssh use from the command line (also known as the terminal, cmd)  on Linux, MacOS, and Windows 10 machines. For serious ssh use on Windows we recommend installing MobaXterm instead.

ssh

ssh ID@computer.domain
e.g. ssh mr349@barbican.ch.cam.ac.uk

man ssh

Connecting directly to a workstation via the bastion host with ProxyCommand

Ensure you have the following blocks in your ~/.ssh/config, replacing WORKSTATION and CRSID as appropriate.

Host WORKSTATION
  User CRSID
  ProxyCommand ssh CRSID@barbican.ch.cam.ac.uk -W WORKSTATIONch.private.cam.ac.uk:22

If you use a non-standard filename for your ssh key, you need to instruct your ssh client to use that for both the connection to the bastion host (barbican) and the subsequent connection to your workstation as follows (now also replacing PRIVATE_KEY_FILENAME).

Host barbican.ch.cam.ac.uk
    IdentityFile ~/.ssh/PRIVATE_KEY_FILENAME
    User CRSID
 
Host WORKSTATION
    IdentityFile ~/.ssh/PRIVATE_KEY_FILENAME
    IdentitiesOnly yes
    User CRSID
    HostName WORKSTATION.ch.private.cam.ac.uk
    ProxyCommand ssh CRSID@barbican.ch.cam.ac.uk -W WORKSTATION.ch.private.cam.ac.uk:22

Then, you can simply ssh WORKSTATION to connect, assuming there are no blocks in your ~/.ssh/config that would override any of the above.

scp

To copy files from the computer you are sitting at (local1) to a remote computer (server1):

scp ./file ID@server1:/home/ID/file
e.g.
mr@chm:~> scp womble.txt mr349@barbican.ch.cam.ac.uk:~
or:
mr@chm:~> scp womble.txt mr349@barbican.ch.cam.ac.uk:~/womble.txt

To copy files from a remote computer (server1) to the computer you are sitting at (local1):

scp ID@server1:/home/ID/file ./file
e.g.
mr@chm:~> scp mr349@barbican.ch.cam.ac.uk:~/womble.txt .
or:
mr@chm:~> scp mr349@barbican.ch.cam.ac.uk:~/womble.txt ./womble.txt

man scp

If you need to do scp from outside Chemistry's firewall to inside it, or vice versa, see https://www.ch.cam.ac.uk/computing/scp-over-ssh-tunnel

sftp

To sftp to a computer called server1.ch.cam.ac.uk

sftp ID@server1.ch.cam.ac.uk
>

for more info:
> help
man sftp

X11 forwarding

ssh -X ID@computer.domain
e.g. ssh -X mr349@barbican.ch.cam.ac.uk

The -X is the option for X11 forwarding and if you are using a medium/slow connection then you might want compression: -C.