Network management of local area network management

Traditional local area network management is mainly for a certain range of local area network, in such a local area network, including the main management objects are: servers, clients, client PCs, various network lines and hubs, as well as a variety of network operating systems. Because in this scale of LAN, network management of limited objects, network management generally includes three aspects: understanding of the network, network operation and network maintenance.1. Understanding of the network

To manage a good LAN, you must have a clear understanding of the LAN. A clear understanding of the network as well as a variety of network information management records, is to ensure that the normal operation of the network as well as a variety of network maintenance prerequisites and foundations. (1) Identify the hardware of the network object: LAN is composed of various nodes, such nodes are mainly servers and clients, so the first need to identify the hardware composition of these nodes. Hardware identification includes understanding the brand of servers and clients, their chip rate, network card brand and configuration, as well as hub models and brands, so that you can understand the hardware equipment providers in the LAN and hardware equipment to achieve a general understanding of the performance. It is also important to have a better understanding of the server's hardware, including the configuration of the server's peripherals, the capacity of the hard disk drives, and the size of the memory.

(2) Discern the topology of the LAN: After understanding the key components of the network you need to further understand how they are connected to operate, i.e. the actual cabling system under the network structure. The three common topologies of cabling are star, bus and ring topologies, and there are also wireless and point-to-point topologies, but they are not commonly used. After understanding the cabling structure of a LAN, the respective advantages and disadvantages for each structure should be noted for the differences in performance and failures they will cause. Then what needs to be understood is the way in which network transmission is realized. The commonly used network transmission method is Ethernet, which is a mature standard that supports a wide range of transmission protocols as well as a variety of cabling forms. ethernet is non-deterministic, the heavier the network transmission task, the more likely that conflicts will occur, and the conflict will lead to an impact on the response time. So there are a large number of active nodes on the network when the performance will be greatly reduced, if the Ethernet hub is always a conflict signal, then, after familiarizing themselves with the network layout may have to reconsider distributing the users on the network.Ethernet cables include: thick Ethernet, or 10Base5 Ethernet, using large coaxial cables; thin cable Ethernet, or 10Base2Ethernet, which uses small-diameter RG-58 coaxial cable; and 10BaseTEthernet, which uses unshielded twisted-pair cable in a star configuration. For the use of Ethernet way of LAN, network administrators should not only be clear about the principle of Ethernet, but also must understand the Ethernet cable and plugs used in networking and their characteristics, so that in the event of network failure can help to find the point of failure and troubleshooting. In addition to Ethernet, other network transmission methods are marked ring (Token Ring), Fiber Distributed Data Interface (FDDl) and ARCNet. Understanding the transmission methods used in LANs is one of the basic requirements for LAN management.

(3) Determining the interconnection of the network: First, you need to determine the devices that will be connected to the network and how they will access the network. These devices and access methods include: using a modem (Modem), using a network socket, using a CSU/DSU connection, working with a bridge, using a router, and using a gateway. These access devices play an important role in ensuring the connectivity of the network nodes and the connectivity of this LAN to the backbone network, as well as being the point of failure where network failures are frequent and the possible bottlenecks affecting the performance of the network. On the other hand, it is also necessary to make sure that all subnets and clients of the LAN are connected on the network server or other network devices, and to record the IP address assignments of the subnets and clients in the network.

(4) Determining User Load and Positioning: The most important aspect of the network load is the distribution of users, since the number of users on each network and server is a key factor in network performance, it is especially important to determine how many users are on the network and their respective positioning. First, look at the load on the file servers to see how long the file servers have been up and running, look at the CPU utilization of the servers, and the number of network connections on the servers, which provide direct data on the network load; then use this data to analyze which of the many servers has the highest utilization and which networks are the most burdened, and finally, get a general idea of the distribution of the network users and the load. to get a general idea of the distribution of network users and loads.

2. Network operation

To make a LAN smooth operation must be completed a lot of work, these work include: configuration of the network, that is, select the network operating system, select the network connection protocol, and according to the selected network protocol configuration of the client's network software; and then configure the network servers and network peripherals, do a good job to prevent network accidents; and finally, there are network security management, network user rights allocation and virus control. management, network user rights allocation and virus prevention and treatment.

(1) configure the network; configure the network to choose the network operating system. Traditional network operating systems include UNIX, Windows NT, NetWare, VINES, Windows for Workgroups, LANtastic, PersonaI Net-Ware, etc. These network operating systems have their own characteristics, relatively speaking, in the local area of the two WindowsNT and Net-Ware is more common. NT's biggest advantage lies in its price and the giant Microsoft that supports its development. NT supports IPX and TCP/IP, so it is popular in most network environments, in addition, its security and network management features are also good when the hardware is fully compatible with the installation is also relatively easy. In the existing network, about 70% of the network operating system used Novell's NetWare series. NetWare is a fast and reliable operating system, very similar to DOS, it has a variety of network protocols and a variety of client operating systems have perfect support, and its compatibility and modular design also make it ahead of other systems.

Choosing a network protocol is also an important part of configuring a network. Popular LAN network protocols today include IPX/SPX, TCP/IP, NETBIOS, NetBEUI, and AppleTalk. The more popular protocols are IPX/SPX and TCP/IP, of which IPX/SPX is the data transmission method used by NetWare and is very commonly used in LANs; TCP/IP is the network protocol used for the Internet, and has a wide reach.

After determining the network operating system and network protocols, you need to configure the network software for each client in that network. On the DOS platform, it is generally to install the network driver software of the corresponding network protocol, and then modify some parameters in the configuration file; in the operating system of the GUI (such as the Windows series, Macintosh and OS2), the corresponding dialog box window is selected to configure the network parameters; in the UNIX system, it mainly relies on the modification of the system configuration file to configure the network.

(2) Configure the network server: in a LAN, the server often has an important role, a well-configured server can smoothly guarantee the operation of the network. The first is to divide the work on the server with disks and volumes according to the nature of the content with the space size allocation, so that different programs and data can be stored in a kind of order in the disk, and the use of volumes can not only store data in a certain level, but also to control the user's right of access, and then start the network service process on the server to monitor the access of network users. There are also peripheral devices such as *** enjoy printers, *** enjoy external disks or drives, etc., which should be properly configured on the server.

The last thing that should also be noted is the prevention of network accidents, first of all, to ensure that the power supply (especially the power supply of the network server), the general way is to configure the UPS emergency power supply; and then to ensure that the environmental conditions of the server (such as maintaining the temperature of the server room and the humidity in a certain range); and finally, to do a good job in the back-up of important data and system backup work. Hardware devices for backup include hard disk arrays and tapes, CD-ROM drives, etc. There are many methods for backup, commonly used are disk mirroring, disk duplexing or disk arrays. When making backups be sure to keep detailed records, categorize and mark the contents of the backup.

(3) Network security control: The first task of network security control is to manage user registration and access rights. On the LAN, the network operating system generally provides tools for user management and permission assignment. For the LAN, the Department of users, the use of these tools can check and set user information, account restrictions, such as changing the account password, set up groups, determine the account in the group, modify the group or account permissions, set the account effective time and so on. Regularly check and record the current access situation of the network to detect abnormal situations in time. In addition, it is also important to manage external LAN privileges and connections, generally external LAN users may access the LAN, such as viewing existing files, transferring their files or using other network resources, so it is also necessary to set up accounts for such users, but their access privileges should be controlled in detail according to the purpose of their using the network, and then periodically check which users are not registered, and log out in time of some accounts no longer required

Virus

The danger of viruses on a LAN is very serious. A network virus can quickly infect every client on the LAN through the network, so it is vital to find and kill viruses in a timely manner. There are a number of different ways to identify viruses: at the file level, with CRC techniques it is possible to compare the expected file size or other characteristics with the actual characteristics seen before the file was opened; the most common method is to scan the file and discover the signs, codes of known viruses, thus recognizing each virus variant. Once a virus is found, it must of course be removed. Using some antivirus software can kill the virus to restore the original file. Another method is to delete the file with the virus and replace it with a backup virus-free file. It is also important to scan the volumes on the virus-infected server, and if there is a communication link between network servers or between clients, you must also go ahead and scan other systems. Determining appropriate ongoing virus protection is the most effective way to avoid virus attacks, and such protection includes: establishing and enhancing anti-virus rules and procedures; installing and updating anti-virus software on client machines; and installing network-based anti-virus software.

3. Network Maintenance

Network maintenance is an important aspect of ensuring the normal operation of the network, which mainly includes fault detection and troubleshooting, daily network checks and network upgrades.

1) common network faults and repair: in the LAN, the most important fault detection work is the maintenance of file servers. As long as the server is working properly, the centrally stored data is safe, and users can access this data when needed. Of course, network-connected devices should ensure that users can work continuously, and the clients themselves should work properly.

The troubleshooting process has four main parts: detecting signs of trouble, tracking down the root cause of the trouble, troubleshooting the problem, and documenting the resolution of the problem. Network troubleshooting often requires a great deal of research, but relatively few problems are truly complex. Commonly, the solution to a fault is simple, only masked by other problems or incomplete information. During troubleshooting, you can refer to the flowchart in Figure 1 to ensure that you can analyze network failures in a logical and organized manner.

When a network administrator receives a trouble report, the first thing he or she should do is check to see if other users are experiencing the same problem. If more than one user is reporting the same type of problem, then it is likely that there is a server or cable failure rather than a failure caused by the user's client.

Troubleshooting errors on file servers is critical because it usually affects many users, so start with a careful inspection of the server: Is the server running? Is the monitor displaying information? Is the server responding to keyboard input? Does the server console display an abnormal termination or other message? Is the server NIC (network adapter) sending and receiving data? Is the server volume installed?

File servers are usually very stable, but they are also particularly susceptible to three types of failures: the first type of failure is not an error in the network operating system itself, but rather is due to a change in configuration, so it is important to back up previous configurations and record the date of the change whenever a change is made to a network operating system configuration; the second type of failure is a component failure, and although NIC and disk failure are the most common, the most common type of failure is from the keyboard port to the disk. most common, but any component from keyboard ports to SIMMs can fail, even on high-quality servers; the third type of failure is system conflict failures caused by software modules of the server, such as memory failures caused by disk drivers or LAN drivers.

When all aspects of the server troubleshooting are in order, the problem that caused the large number of user access failures is likely to be in the network cable system. If the faulty network has a bus topology, fault detection may be more onerous; for a star structure, check that the hubs or MAUs are powered up and functioning properly. If the connected devices themselves are functioning well, check their physical connection to the server. In general, for physical networks, aging cables and pushbuttons, electromagnetic interference, and cable length limitations are the most common sources of physical network failures; connecting devices, such as patch panels, hubs, and routers are also failure-prone.

(2) Network checking: Network checking is the process of collecting and analyzing dynamic information about the status of servers and the operation of the network under normal network operation. Some data is best checked once a day, while some data can be checked once a longer period of time. The following is a list of some key information about the network that needs to be checked on a regular basis: Frequency Activity Frequency Activity Daily Check the volume space of each server Daily Remove old users Daily List the corpora created on the previous day Monthly Check the security of user accounts Daily Identify old files that can be archived/deleted Monthly Ensure the completeness of the backups Daily Check the backups are executed Monthly Change the server modules Daily Check the server error log files Monthly Update client files (3) Network upgrades: Network upgrades are an ongoing process which requires some financial and budgetary considerations. Generally the upgrades that need to be considered in network management are the ones that have to be performed, which keep the network functioning properly. While network operating system upgrades are usually the most pressing, hardware and software upgrades may also be required.

Server upgrades are the most important. There are three types of necessary server upgrades: the simplest is a user license upgrade, if the capacity of the network server has reached its maximum limit and needs to accommodate more users, it is necessary to carry out license upgrades; another two types of server upgrades is the upgrade of the network operating system, if the use of outdated or faulty network operating system, it should be upgraded to the latest version; the third server upgrades referred to in the range of The third type of server upgrade is relatively broader in scope, mainly referring to hardware upgrades, which may include increased disk space, improved fault tolerance measures or system upgrades. In addition, client software upgrades are sometimes necessary because old client software can be a heavy burden on the network operating system.

After identifying the most important upgrades, a decision should be made about the products that need to be purchased and the cost of the upgrades should be evaluated, then the work steps to implement the upgrades should be developed, and finally, the advantages of the new configuration should be summarized in terms of both costs and benefits.