Filezilla remote tunneling instructions

_episodes/16-transferring-files.md

@@ -448,6 +448,8 @@ Hit "Quickconnect" to connect. You should see your remote files appear on the
 right hand side of the screen. You can drag-and-drop files between the left
 (local) and right (remote) sides of the screen to transfer files.
 
+{% include {{ site.snippets }}/transferring-files/filezilla-ssh-tunnel-instructions.snip %}
+
 Finally, if you need to move large files (typically larger than a gigabyte)
 from one remote computer to another remote computer, SSH in to the computer
 hosting the files and use `scp` or `rsync` to transfer over to the other. This

_includes/snippets_library/UCL_Myriad_sge/transferring-files/filezilla-ssh-tunnel-instructions.snip

@@ -0,0 +1,21 @@
+> ## Connecting Remotely Via an SSH Tunnel
+>
+> If you are remote and not using a VPN, you will need to set up an SSH tunnel
+using your terminal.
+>
+> ```
+> {{ site.local.prompt }} ssh -L 3333:{{ site.remote.login }}:22 {{ site.remote.user }}@ssh-gateway.ucl.ac.uk -N
+> ```
+> {: .language-bash}
+>
+> This connects the local port 3333 to the cluster's SSH port, via the
+> remote gateway. The `-N` option tells it not to execute any remote
+> commands. Leave this running in the terminal and in FileZilla, set
+>
+> * Host: `sftp://localhost`
+> * User: Your cluster username
+> * Password: Your cluster password (leave blank to use your SSH keys)
+> * Port: 3333
+>
+> Hit "Quickconnect" to connect.
+{: .callout}