Give the network three ways to test the network

Network faults are so strange. How can we effectively solve network faults and give a correct conclusion to the "healthy" Situation of the network? This article describes the network test based on the network hierarchy and network tester.

According to statistics, 35% of network faults are at the physical layer, 25% at the data link layer, 12% at the network layer, 10% at the transmission layer, 8% at the conversation layer, 7% at the presentation layer, and 3% at the application layer. It can be seen that network faults usually occur on the lower layer of the layer-7 network model, that is, the physical layer, link layer, and network layer. Corresponding to the actual network, that is, the network cable, connection module, network adapter, switch, router, and other equipment faults we use. These faults may occur frequently due to product quality or performance, wear and aging, human error, incorrect settings, and management defects. The consequence is light, which affects the information transmission of a single site. Heavy traffic may lead to downtime of important network devices, such as servers, switches, and routers, resulting in paralysis of the entire network.

1. Site-Level Test

By checking physical connectivity, connection matching, protocol matching, and data sending and receiving correctness, this test solves most of the problems that a single site cannot connect to the network. Generally, the cabling system of the network should undergo a comprehensive test at the certification level. No fault affecting connection and communication will occur in special cases. In daily network maintenance, cable faults are often caused by terminal connection errors caused by PC movement and jumper insertion and removal, such as virtual connection at the Jumper crystal head, virtual connection to the wall module, and pin connection.

We use the network connection fault diagnosis function of Fluke's network multimeter to solve the above problems. It can determine the cable connection line sequence error, open Short Circuit Error and occurrence point. If the network cable passes the test, we can check the hardware settings of the network device, including receiving line pairs, rate and duplex mismatch, low signal level value and other issues, which are physical layer diagnostics. It is very likely that a duplex mismatch problem causes slow network traffic, but few people can think of the problem.

The link layer tests are mainly frame-level errors and frame-level traffic tests, which are also known as network health tests, including utilization, broadcast, collision, and error analysis. The tester can accurately test the network traffic type and even tell us the root cause of the error. The Network multimeter can be used to help network managers identify and solve the link traffic problems in a short time.

For the network layer, the powerful advantage of the site-level tester is that it can compare the matching between the protocols in the network and those used by the site without interrupting the site traffic. You can easily find the network through the instrument, but there is no expected protocol type on the site. Do you need to restart your computer? The problem may be solved.

2. workgroup-level testing

The network test explains how to test in a shared network based on OneTouch. Although Network Fault failover is also a network tester for the next three layers, this instrument has included testing of the entire network segment, which can monitor network traffic, you can also search, classify, and count devices and protocols of CIDR blocks. When your network is facing heavy traffic, you can also use the traffic generation function of the tester to view the network affordability in advance. As an important part of the experiment, we will also instruct trainees to complete some practical maintenance functions through the tester. For example, how to find the location of the terminal connected to the distribution frame and the Port location of the network device, how to find the switch and port number connected to the terminal through the terminal IP address and MAC address, etc, these are the things that network administrators often need to spend a lot of time doing.

Network Fault failover is the smallest handheld Network Tester Based on Traffic tests. When network administrators need to test the shared network or an important network device, the role of Network Fault failover will be fully realized.

3. Test the exchange environment

The switching environment optimizes the network structure and effectively divides conflicting domains. However, the emergence of the switching environment is like a black hole for network testing. The sharp testing capability of the network tester is lost in this black hole. How to gain insight into network traffic, discover faults, and solve faults in an exchange environment, and how to make the functions of the network tester stand out again has become what everyone expects. Systematic Analysis of the health status of the entire network is no longer as direct and easy as a shared network. How can this problem be solved? In the anheng network experiment, we will introduce several testing methods in the exchange network, including both software and hardware. Implements a comprehensive network test in the exchange environment by combining hardware and software.