How to create a TCP listener?
You could use nc -l
as a method to do what you are looking for. Some implementations of nc
have a -L
option which allows the connections to persist.
If you only need them for a little while you could open this command in a for
loop and have a bunch of ports opened that way.
If you need these opened longer you can use one of the super servers to create a daemon.
you can create a port listener using Netcat .
root@ubuntu:~# nc -l 5000
you can also check if port is open or not using netstat command .
root@vm-ubuntu:~# netstat -tulpen | grep nc
tcp 0 0 0.0.0.0:5000 0.0.0.0:* LISTEN 0 710327 17533/nc
you can also check with nc :
Netcat Server listener :
nc -l localhost 5000
Netcat Client :
root@vm-ubuntu:~# nc -v localhost 5000
Connection to localhost 5000 port [tcp/*] succeeded!
if port is not open
root@vm-ubuntu:~# nc -v localhost 5000
nc: connect to localhost port 5000 (tcp) failed: Connection refused
Listen using netcat.
# nc -l 5555
Check using ss
# ss -nat|grep 5555
LISTEN 0 1 *:5555 *:*
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