Iptables only allows the specified IP address to access the specified port

Iptables only allows the specified IP address to access the specified port

First, clear all pre-settings

Iptables-F # clear rules of all rule chains in the filter of the preset table
 
Iptables-X # Clear the rules in the User-Defined chain in the filter of the preset table

Second, set to allow only the specified IP address to access the specified port

Iptables-a input-s xxx. xxx-p tcp -- dport 22-j ACCEPT
 
Iptables-a output-d xxx. xxx-p tcp -- sport 22-j ACCEPT
 

 
Iptables-a input-s xxx. xxx-p tcp -- dport 3306-j ACCEPT
 
Iptables-a output-d xxx. xxx-p tcp -- sport 3306-j ACCEPT

Note that -- dport is the destination port. When data enters from the external server, it is the destination port. Otherwise, data goes out from the server as the data source port, and -- sport is used.
Similarly,-s specifies the source address and-d specifies the target address.

Disable all ports.

Iptables-P INPUT DROP
 
Iptables-P OUTPUT DROP
 
Iptables-P FORWARD DROP

Finally, save the current rule

/Etc/rc. d/init. d/iptables save
 
Service iptables restart

This iptables rule setting applies only to the management and maintenance of MySQL servers. External addresses do not provide any services.

If you want yum to run, you also need to add the following content to allow the DNS request to port 53 and allow the random download of high ports

Iptables-a input-m state -- state RELATED, ESTABLISHED-j ACCEPT
 
Iptables-a input-p udp -- sport 53-j ACCEPT
 
Iptables-a output-m state -- state RELATED, ESTABLISHED-j ACCEPT
 
Iptables-a output-p udp -- dport 53-j ACCEPT
 
Iptables-a output-p tcp -- sport 10000: 65535-j ACCEPT
 
/Etc/rc. d/init. d/iptables save
 
Service iptables restart

For more iptables tutorials, see the following:

Disable the default firewall in CentOS 7.0 and enable the iptables firewall.

Iptables examples

Linux Firewall iptables

Basic use of iptables backup, recovery, and firewall scripts

Detailed description of firewall iptables usage rules in Linux

Iptables firewall settings in Linux

This article permanently updates the link address: