ssh -L (error: bind: Address already in use)

Couldn't you just kill whatever is using that port?

 lsof -ti:5901 | xargs kill -9

lsof -ti:5901 to find whatever is using port 5901.

Pass the whole thing to kill -9 to kill whatever was using port 5901.

Replace with the port you want to open up again.

I suppose you have still something connected to local port 3000.

You can find it with

netstat -tulpn | grep 3000 

and then dispose of it. For example in my machine:

[:~] % netstat -tulpn | grep 5900
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp        0      0 0.0.0.0:5900            0.0.0.0:*               LISTEN      2547/vino-server
tcp6       0      0 :::5900                 :::*                    LISTEN      2547/vino-server

correctly identifies the process waiting and connected on port 5900 (vnc server).

Another useful command is

fuser 3000/tcp 

...all of them may need to be run with sudo if you do not own the process which is opening the port.

I was able to recreate and fix it by doing the following:

• Open up something that will list your processes (ps -ae)
• Kill the process called sh (kill <proc_number>)

Then reopen the ssh connection

Alternatively, I have had success with:

killall ssh

In the terminal on the local machine