Which of the following objects of the container network model (CNM) contains the configuration files of a container's network stack, such as routing table, container's interfaces, and DNS settings?

In the Container Network Model (CNM), the Sandbox is the object that represents an isolated network environment for a specific container. It encapsulates the container's entire network stack configuration, which includes its network interfaces (represented as endpoints), the routing table, and DNS settings. Each container has its own unique sandbox, ensuring network isolation from other containers and the host system. This is commonly implemented using a Linux network namespace.

A. Endpoint: An endpoint is an interface that connects a sandbox to a specific network. It does not contain the entire network stack but is rather a component within it.
C. Network drivers: Network drivers are responsible for the implementation of a network (e.g., bridge, overlay). They provide the connectivity but do not hold the per-container stack configuration.
D. IPAM drivers: IPAM (IP Address Management) drivers are solely responsible for allocating and managing IP addresses for networks and endpoints, not the container's overall network stack.

1. Docker Official Documentation (libnetwork): The design document for libnetwork, Docker's implementation of the CNM, explicitly defines the Sandbox. It states, "A Sandbox is a container's network stack. This contains the container's network interfaces, routing table and DNS settings... A Sandbox may contain many endpoints from multiple networks."

Source: Docker libnetwork GitHub Repository, design.md. Section: "The Container Network Model". (https://github.com/moby/libnetwork/blob/master/docs/design.md)

2. University Courseware: Course materials on cloud computing and distributed systems often cover container networking architecture, referencing the CNM. Lecture notes describe the sandbox as the component providing network isolation and containing the network stack for a container.

Source: University of Illinois Urbana-Champaign, CS 425 / ECE 428: Distributed Systems, Fall 2021, Lecture 11: "Containers: Docker". Slide 31 discusses the Container Network Model, identifying the Sandbox as the container's network stack.