CentOS View port usage and open port commands

1. CentOS View Port occupancy

For example, check the 80 port occupancy using the following command:

Lsof-i tcp:

2. List all ports

Netstat-ntlp

3. Open port (take port 80 as an example)

3.1 Method One:

Write modifications

 -j ACCEPT

Save changes

/etc/init.d/iptables Save

Restart firewall, modify to take effect

Service Iptables Restart

3.2 Method Two:

Open the configuration file by adding the following statement:

VI /etc/sysconfig/iptables

Add to

 -j ACCEPT

Restart firewall, modify to take effect

Service Iptables Restart

4. Close the port

4.1 Method One:

Write modifications

 -j DROP

Save changes

/etc/init.d/iptables Save

Restart firewall, modify to take effect

Service Iptables Restart

4.2 Method Two:

Open configuration file

VI /etc/sysconfig/iptables

Add to

 -j DROP

Reboot firewall, modify complete

Service Iptables Restart

5. View port Status

/etc/init.d/iptables status

CentOS View port usage and open port commands