Can't forward to port 8787

Question

We have an instance of R studio running on port 8787 under Ubuntu 16.04.5 LTS. We can access it normally from work using:

server_url:8787

When not at work, after connecting to work VPN, we normally set an ssh forward using:

ssh -N -f -L localhost:8787:localhost:8787 username@server_url

And then, access R studio through a browser using the address:

localhost:8787

Recently, we have been unable to access R studio from outside work (from work, it is still fine)

Forwards to other ports continue to work normally, but forwards to port 8787 don't seem to work anymore.

Any reason what could be causing this and/or how can I properly diagnose? Any help will be highly appreciated.

Did you check your local Port 8787? SSH port redirecting will not work, if the port is already occupied. — bjoster, Apr 18 '19 at 15:31
If you are on VPN, why do you need the port forwarded in an ssh tunnel? You should just connect normally, as you do from work. — Michael Hampton, Apr 18 '19 at 15:53
@MichaelHampton, we can access the server through ssh, but when we need to access a specific port on a broswer, we can only do it through a port forward. For instance: ssh username@server_url from command line works, but server_url:3000 in a browser does not work, we need to do: ssh -N -f -L localhost:3000:localhost:3000 username@server_url and then access it on a browser using localhost:3000 — Ali Hassaine, Apr 18 '19 at 16:08
You should not need to do that at all! That is the point. Something is wrong with your VPN. — Michael Hampton, Apr 18 '19 at 16:09

score 0 · Accepted Answer · edited Jul 09 '20 at 16:25

0

It turned out that one of my colleagues ran the following command from the server instead of running it from the client:

ssh -N -f -L localhost:8787:localhost:8787 username@server_url

After killing the corresponding process, port forwarding is working as expected.

edited Jul 09 '20 at 16:25

kenlukas

answered Jul 09 '20 at 15:36

Ali Hassaine

1 Answers1