View the usage of ports under Linux

Netstat-tln

The meaning behind the netstat

· Proto shows the protocol used by the connection.
· REFCNT represents the process number that is connected to this set of interfaces.
· Types shows the type of the socket interface.
· State displays the current status of the socket interface.
· Path indicates the pathname used by other processes connected to the socket

The NETSTAT-TLN command is used to view the port usage of Linux.

NETSTAT-A View all service ports

Netstat-an | grep Port number to check if a port has been opened

Service xxx Start or/etc/init.d/xxx start is to open XXX port

iptables-a INPUT--dport xxx-j DROP
iptables-a OUTPUT--dport xxx-j drop is off the xxx port

View the usage of ports under Linux