Sometimes when you try to run a port through terminal, you may end up getting errors like 'address already in use'.

I get this even when I disconnect the host. Although it happens sometimes only. Follow this steps to Kill the local Host.

Step 1:
Open Your Linux Terminal

Step 2:
Types this command below.
sudo lsof -iTCP:3000 -sTCP:LISTEN
Please note that: type your port address instead of 3000

Step 3:
You get an output similar to this.

COMMAND   PID   USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
node    25215  user    20u  IPv6 240148      0t0  TCP *:hbci (LISTEN)

note that PID

Step 4:
type kill 25215

Voila, you killed it :)