关闭Linux系统的防火墙（关闭linux的防火墙）

Firewall is a set of related rules and/or programs designed to prevent unauthorized access to your system, including network access, data bases and other types of general system services. For Linux system, there are some utilities that can provide firewall protection. In this article, I will show you how to use the iptables command to disable the Linux system firewall.

Before we start, make sure you have root (or sudo) access to the system.

The first step to disabling the Linux system firewall is to flush all existing rules:

iptables -F 

To remove all your chains (INPUT, FORWARD, OUTPUT):

iptables -X 

The third step is to set the default policy for all three chains to “ACCEPT” (instead of “DROP”):

iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

Now that we have disabled the firewall, make sure you secure your system using other means such as a host-based intrusion detection system (HIDS), virtual private network (VPN) and open source vulnerability assessment tools.

If you ever need to re-enable the firewall, start by resetting the default policy to “DROP”:

iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP

Then add the firewall rules that you need.

In conclusion, disabling the Linux system firewall is relatively easy using the iptables command. Just remember to use other methods for securing your system, since the firewall is only one of many security measures.