Practical Tips: how to set up a Linux system firewall

Article Title: Practical Tips: how to set up a Linux system firewall. Linux is a technology channel of the IT lab in China. Including desktop applications, Linux system management, kernel research, embedded systems, open-source, and other basic categories. To modify firewall configurations, You need to modify the/etc/sysconfig/iptables file. If you want to open the port, add one.

-A RH-Firewall-1-INPUT-m state -- state NEW-m tcp-p tcp -- dport 1521-j ACCEPT

1521 indicates the port number to be opened, and then restart the Firewall Service in linux.

Command to stop/start the Firewall Service:

Run

Service iptables stop -- stop

Service iptables start -- start

(The service command is located in/sbin)

Firewall Rules can be activated only when the iptables service is running. To manually start the service, run the following command:

/Sbin rvice iptables restart

To ensure that it is started during system boot, run the following command:

/Sbin/chkconfig -- level 345 iptables on

The ipchains service cannot run with the iptables service at the same time. To disable the ipchains service, run the following command:

/Sbin/chkconfig -- level 345 ipchains off