CentOS View port usage and open port commands

CentOS View port occupancy commands, such as view 80 port occupancy using the following command: Lsof-I. tcp:80
List all ports netstat-NTLP
1, open port (take port 80 as an example)
Method One:/sbin/iptables-i input-p Tcp–dport 80-J ACCEPT Write modification/etc/init.d/iptables Save ChangesService iptables Restart Restart Firewall, modification takes effect
Method Two: VI/etc/sysconfig/iptables Open the configuration file by adding the following statement:-a input-p tcp-m state–state new-m Tcp–dport 80-J ACCEPT Reboot firewall, modify complete
2, close port method one:/sbin/iptables-i input-p Tcp–dport 80-J DROP Write modification/etc/init.d/iptables Save ChangesService iptables Restart Restart Firewall, modification takes effect
Method Two: VI/etc/sysconfig/iptables Open the configuration file by adding the following statement:-a input-p tcp-m state–state new-m Tcp–dport 80-J DROP Reboot firewall, modify complete
3, view port status/etc/init.d/iptables status

CentOS View port usage and open port commands