Displays network-related information such as open connections, open socket ports, etc.

# To view which users/processes are listening to which ports:
sudo netstat -lnptu

# To view routing table (use -n flag to disable DNS lookups):
netstat -r

# Which process is listening to port <port>
netstat -pln | grep <port> | awk '{print $NF}'
# Example output: 1507/python

# Fast display of ipv4 tcp listening programs
sudo netstat -vtlnp --listening -4

# ---

# To list all ports:
netstat -a

# To list all listening ports:
netstat -l

# To list listening TCP ports:
netstat -t

# To display PID and program names for a specific protocol:
netstat -p <protocol>

# To list information continuously:
netstat -c

# To print the routing table:
netstat -nr