200-301 braindump

200-301 braindump.Problem isolation: this step maintains the same answer, specifying what is not working? When certain failures occur, the components that are not working properly are found by comparing them to the expected performance, still referring to the documentation, configuration, and the output of the show and debug commands. Root cause analysis: this step answers the question, what is the problem that we can identify to solve? Based on the problems identified in the previous steps, identify the potential causes of the problem and then take appropriate actions to fix the failure in response to those causes.By following these 3 steps, administrators will know how to fix the problem instead of just scratching the surface. The next section describes how to apply each step in the troubleshooting process.1. Analysis and prediction of normal network operationThe task of all networks is to send data from one end-user device to another. The administrator must understand the logical relationship of each connected device forwarding data to the next device in order to analyze the network. By considering what is happening at each device, the administrator can describe the entire data flow.The DataPlane is the operation taken by a network device to forward packets. The device applies its own DataPlane logic and operational processing to each frame or packet, which in turn accomplishes the task of forwarding frames and packets. For example, a LAN switch receives a frame on one of its interfaces in VLAN 3, and that switch makes a forwarding decision based on the entry for VLAN 3 in the MAC address table and forwards this packet. All this logic is primarily used to forward user data, so its said to be part of the switch data platform processing.Control platform (ControlPlane) refers to the additional overhead process that does not work through network device control but does not directly affect the forwarding of frames or packets. For example, Spanning Tree Protocol (Spanning Tree Protocol, STP) and IP routing protocol are examples of control platform processing.Other control-platform processes do not even indirectly change the way a device forwards data. For example, Cisco Discovery Protocol (CDP) can be used to verify the accuracy of network records, but even if CDP is disabled, it does not have any effect on the data platform forwarding process.CDP is also part of the control-platform processing.In order to predict the desired network operation, or to describe in detail how the network is currently working so that it functions properly, it is helpful to start by looking at the control platform or the data platform. The following begins with an analysis of the data platform. Of course, in realistic situations, then different platforms can be targeted for analysis based on known failure phenomena. (1) Analysis of the data platform1.2 Basic content 51The troubleshooting process for a data platform involves examining each device sequentially along the expected data forwarding path. The entire analysis process begins with the host that created the initial data. That host sends data to other devices, then the device that received the data sends data to another device, and so on in sequence until the data reaches the end host.