Linux connection problems

From #39:

While trying to set up jupyter on scalc01, I stumbled across a similar issue.

I am using a linux machine OD-NB010LX. Starting jupyter-lab from the base env on scalc01 works but when I try to set up the tunnel with chromium, I also get

This site can’t be reached
127.0.0.1 refused to connect.
Try:
Checking the connection
Checking the proxy and the firewall
ERR_CONNECTION_REFUSED

@gabriel-ditzinger: Can you give details on how exactly you start the tunnel?