LIACS VPN

Some resources at LIACS are only accessible when you are at LIACS or going through the LIACS VPN. Here we explain how to get access to those resources by setting up a SOCKS5 proxy and setting your browser to use that proxy when needed.

• https://rel.liacs.nl
• https://docs.liacs.nl

Setting up a system-wide VPN access on your computer could be troublesome. Luckily, now even Windows includes the SSH tools in their base system. The following instructions apply to Windows, MacOS and Linux.

To check if you have a key you can use

ssh-keygen -l

If there is no key, you can generate one with

ssh-keygen

You can skip this step but you will have to enter your password every time you connect to the server.

The easiest way to share your public id with the server is to use

ssh-copy-id <your ULCN>@ssh.liacs.nl

Enter your password to transfer the key.

Windows Unfortunately, this command isn't available under Windows (why?)! Instead use this

type %userprofile%\.ssh\id_rsa.pub | ssh <your ULCN>@ssh.liacs.nl "cat >> .ssh/authorized_keys"

We recommended installing some extension to manage the proxy. FoxyProxy is available both in Firefox and Chrome. Install and set up a new proxy connection (type: SOCKS5, proxy IP address: localhost, port: 9999).

To create a SOCKS5 proxy run the following command

 ssh -D 9999 -N <your ULCN>@ssh.liacs.nl

This open a SOCKS5 proxy tunnel listening on port 9999 of your computer, which will redirect the communication to the `ssh.liacs.nl` server. The `-N` prevent the execution of command on the remote shell. You can choose another port if you which but make sure to adapt the configuration of the proxy in your internet browser.

Click on the extension button and activate the proxy.

Note that when the proxy is activated, all the traffic of your internet browser is rerouted through the VPN. Using FoxyProxy you can set it so that only specific websites are rerouted if you want.