JN0-213 Practice Exam Questions with Answers Cloud Associate (JNCIA-Cloud) Certification

contrail-k8s-kubemanager is the component in the CN2 architecture that integrates with the orchestrator (such as Kubernetes or OpenShift) to listen for changes and take action on any events affecting network resources. According to the CN2 components documentation2, contrail-k8s-kubemanager is “the interface between Kubernetes resources and Contrail resources” that “watches the kube-apiserver for changes to regular Kubernetes resources such as service and namespace and acts on any changes that affect the networking resources”. Other components in the CN2 architecture are contrail-k8s-apiserver2, which is an aggregated API server that manages all Contrail resources; cni.bin, which is a binary file that implements the Container Network Interface (CNI) specification for CN2; and contrail-vrouter-agent, which is a pod that runs on every node and communicates with the CN2 control plane to program the data plane.

The cloud computing feature that automatically increases or decreases the resources based on the demand is known as rapid elasticity1112. In cloud computing, scaling is the process of adding or removing compute, storage, and network services to meet the demands a workload makes for resources in order to maintain availability and performance as utilization increases11.

The openstack user list command uses the Keystone service, which is the identity service for OpenStack. Keystone provides authentication, authorization, and service discovery for OpenStack. It also manages projects, users, roles, and endpoints for the OpenStack services

There are two available installation methods for an OpenShift cluster. One is the installer-provisioned infrastructure method56, and the other is the user-provisioned infrastructure method56. References from Juniper site: VMware NSX Container Plugin, OpenShift Container Platform 4.10 Documentation

To run a container in a Kubernetes environment, you should define a YAML manifest for the container and its resources2. YAML manifests are used to define Kubernetes objects, such as pods or services. These manifests describe the desired state of the system2.

 In a CN2 deployment using Kubernetes as the orchestrator, the vRouter agent is contained in the worker node. The vRouter agent is responsible for managing the forwarding plane on each node in a Contrail cluster. It interacts with the kernel to manage the services and interfaces within the virtual networks.

Network Functions Virtualization (NFV) is a network architecture concept that uses IT virtualization technologies to virtualize entire classes of network node functions into building blocks that may connect or chain together to create communication services3. The NFV framework explains how Virtual Network Functions (VNFs) fit into the whole solution4. The NFV Infrastructure (NFVI) is a component of NFV that consists of the infrastructure components —compute, storage, networking—on a platform to support software4. References from Juniper site: Red Hat, VMware, Wikipedia

In OpenShift, the worker node is used to host your application containers1. Worker nodes are where all your coding adventures happen, and they can be virtual or physical1. References from Juniper site: IBM Developer

he free -h command in Linux displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel89. The cat /proc/meminfo command displays real-time information about the system’s memory usage as well as the buffers and shared memory used by the kernel1

A CN2 controller communicates with CN2 vRouters using XMPP (Extensible Messaging and Presence Protocol) and with other CN2 controllers using BGP (Border Gateway Protocol). XMPP is used for control plane communication, while BGP is used for routing updates between controllers.

In OpenStack networks, it is possible to share networks with other projects7. Also, it is possible to enable DHCP for a subnet in an OpenStack network7. References from Juniper site: OpenStack Documentation

Control groups (cgroups) is a Linux kernel feature that limits, accounts for, and isolates the CPU, memory, disk I/O, and network usage of one or more processes678. It allows you to allocate resources among user-defined groups of processes running on a system. You can monitor the groups of processes, deny the groups of processes access to certain resources, or even freeze groups of processes

The Kubernetes object definition file is in YAML format789. Kubernetes objects are represented in the Kubernetes API, and you can express them in .yaml format7. You can execute kubectl get deployment -o yaml to get the deployment definition in a yaml format8.