014.01.56.2. In the context of Linux, how are firewall rules organized, and what is the relationship between chains and tables in the iptables system? Provide an overview of the packet flow through these chains in the Linux networking subsystem.
Firewall rules are arranged in a series known as a chain. A set of chains makes up a table. As a packet moves through the various parts of the Linux networking subsystem, the kernel applies the rules in certain chains to the packets. For example, a new packet arriving from a physical layer in the kernel is classified as "input" by the kernel, so it activates rules in chains corresponding to the input.
In the context of Linux, firewall rules are organized into a series called a chain, and these chains collectively form a table within the iptables system. The relationship between chains and tables is essential for managing network security effectively.
As a packet traverses through different stages of the Linux networking subsystem, the kernel applies specific rules within these chains to the packets. For instance, when a new packet arrives from the physical layer, the kernel classifies it as input and triggers the application of rules within the corresponding input chain. This systematic arrangement allows for a structured and customizable approach to filtering and managing network traffic in Linux.
