What is IPTables?

IPTables is a utility in Linux for configuring and managing network traffic filtering rules at the kernel level. It allows creating a set of rules that determine which packets to accept, reject, or redirect, thereby providing basic protection and access control to the network.

IPTables works with tables (filter, nat, mangle, etc.) and chains of rules (INPUT, OUTPUT, FORWARD), where each rule contains conditions and actions. For example, you can allow access to a specific port or block an IP address.

An example command to allow incoming traffic on port 80:

iptables -A INPUT -p tcp --dport 80 -j ACCEPT