Excellent network maintenance 4

Shared Internet access through routing is frequently dropped Q: An error occurred when using ADSL shared Internet access: Use a Broadband Router (TP-link tr460) to connect two machines and set it to automatic connection, an instant disconnection occurs on the Internet (drops every 20 minutes). view the route system log. The following message is displayed: "The server needs to disconnect the received PAdT ". If no router is installed, a host directly connects to the "cat. How can this problem be solved? A: There are two possible problems: first, the router settings. In some router settings, if the line is idle for a certain period of time, the connection is automatically disconnected. If this problem occurs, set "never disconnect" in your Broadband Router ". Another problem is that China Telecom has set (by binding a MAC address) to restrict the use of routing to access the Internet. You can "clone" the MAC address of your ADSL modem to a Broadband Router for use. File Sharing response is too slow Q: In the past, when I used a hub to access the Internet, files could be shared smoothly with each other. Since I used a vro, my machine can see shared files in the network neighbors, you can access other machines, but when you drag the files they share into my machine, either the response is lost or the speed is very slow. What is the fault? A: "sharing among other machines is normal." It indicates that your network and hardware are correct. The fault should occur at the end of your machine to the vro port. This part includes the ports of faulty machines, NICS, network cables, and switching devices. Please use the replacement method to solve the problem: 1. Check the line sequence of the network cable and whether the network cable is faulty. 2. Insert the network cable to another port of the switch device. 3. check whether your machine, NIC driver is installed and set properly, whether firewall software is installed, whether the software has a faulty operating system and settings or other programs. In addition, check whether the NIC is faulty and you can use the replacement method to solve the problem. Also, check the BIOS settings. 4. Replace the NIC of the faulty machine to check whether the NIC is compatible. DHCP service subnet mask allocation Q: I use ADSL Broadband to access the Internet. I use a vro and then connect to a 16-port switch (IP address allocated through DHCP). Recently, some machines are always unable to access the Internet through the LAN, after using the ping command, it is found that the IP address and gateway are correct. Only the subnet mask is different, which is 255.0.0.0. These computers cannot connect to the LAN. How can this problem be solved? A: different subnet masks cannot access each other. Your problem is that DHCP does not correctly assign IP addresses to computers in the LAN. This should be caused by incorrect DHCP settings. First, the DHCP server must have a static address, and the subnet mask should be what you need (255.255.255.0 in this article). When creating the scope, you must correctly set the allocated address range, subnet mask, gateway, DNS, and other parameters. Check the DHCP server or router in your network. If you use its DHCP service function, check whether the settings are correct. In addition, check whether other DHCP servers are working and other DHCP servers exist in the network. Disable the DHCP server you are using to check whether the DHCP client can obtain the IP address, if yes, other DHCP servers exist. Implementation of load balancing in the KTV karaoke System Q: Can I use the network load balancing technology to implement the KTV karaoke system? A: This is easy to implement. The main method is as follows: 1. If you use three computers for load balancing, your karaoke interface is probably similar to the IE interface. Install IIS on each machine and install the karaoke system. The IP addresses of each machine must be in the same CIDR block, but cannot be the same, for example, 192.168.1.1, 192.168.1.2, and 192.168.1.3. Each karaoke system uses its own services to set related addresses and mappings. 2. enable the network load balancing function on each computer, and set the network load balancing address to 192.168.1.5. 3. log on to each client using 192.168.1.5. The network load balancing technology automatically forwards requests for 192.168.1.5 to different machines.

Reply

Reply: Always happy (posting: Level 5 member credit: 120 points: 2227) 2005-1-24 8:21:40 Enter a password to access the Web server. Q: I have set up a Web server (using IIS), but I have to enter a password every time I use IE to browse. What is the problem? A: Open "Internet Information Service" from "program> Administrative Tools", and click "Computer Name> website> default website" in sequence ", right-click "default website (if you create a new website, click the site you created)" and click the "Directory Security" tab, in "Anonymous Access and authentication control", click "edit" to go to the "authentication method" dialog box, and confirm that "Anonymous Access" and "allow IIS to control the password" are selected ", cancel "Integrated Windows Authentication" and "Basic Authentication (if selected )". You can return the result. In addition, if you have set the NTFS access permission for the Web home directory, you should restore it to the default value of the system and allow everyone to have the read permission. Restrictions on concurrent access IP addresses Q: I used IIS to set up a server and run the netstat-Na command on the server to check the connection. I found that there were a large number of HTTP requests (more than 500 connection requests) connected to port 80 on the site, is there any good solution? A: You can solve the problem by setting IIS. Go to Internet Information Service from Administrative Tools, right-click a website, and select Properties to go to the Directory Security tab, click the "edit" button in "IP address and domain name restriction". In the displayed dialog box, select "authorized access (selected by default)" and click "add, "deny the following access" will pop up and select from "type: 1. If you want to restrict a computer, select "single host" and enter the IP address you want to restrict in "ip address; 2. if you want to restrict a group of computers, select "one group of computers", enter the desired subnet CIDR Block in "network ID", and enter the corresponding value after "subnet mask, to limit 111.222.1.1 ~ For the IP address range 111.222.1.255, enter 111.222.1.0 and 255.255.255.0 In the subnet mask. For example, to disable 111.222.1.1 ~ For computer access in the 111.222.1.255 network segment, the network ID should be 111.222.1.0, And the subnet mask should be 255.255.255.0. Click OK to return. 3. If you want to restrict a domain name, select "Domain Name" and enter the domain name you want to restrict below. For example, if the XXX. Zzz domain name is restricted, you must enter XXX. Zzz instead of www. XXX. Zzz. In addition, this operation restricts a batch of domain names at all levels on the primary domain, and limits the entire XXX. all hosts in the ZZZ domain name, this operation requires IIS to perform a large number of DNS reflection queries, the traffic is relatively large, do not use it easily. Communication between different subnets Q: There are two computers in the CIDR blocks A and B, and the IP address of machine A is 15. XX. xx.7, IP address of host B is 18. XX. xx.10, the two network segments have been connected to the Internet and can ping each other. Can I enable machine B to connect to the Internet without the gateway in the B network segment? If yes, how do I set it? A: In a TCP/IP network, only computers in the same network segment can communicate with each other. The gateway is the egress connecting to another CIDR block. That is to say, to communicate with other networks (including the Internet), a computer must use a gateway. Generally, Gateway communication involves two IP addresses, one is the IP address of the local network, the other is the IP address of the remote network, and the communication between the two networks is routed or switched by the gateway. Because the computer in the B network segment cannot access the IP address of the network segment, even if the computer in the B network segment is set to the Gateway in the network segment, communication will fail because the computer in the B network segment cannot access the gateway, so that computers in the B network segment can only access the local network. Therefore, the gateway must be in the same network segment as the workstation. Breakthrough in the maximum number of domain accounts Q: The server and workstation are both Win2000 systems. When the workstation is added to the domain, the system prompts "the maximum number of computer accounts allowed to be created in the domain has been exceeded. Please reset or add a limit ", the computer account on the domain is only valid for about 30 days. How can this problem be solved? A: In the "control panel" window, double-click the "Authorization" icon to display the "select authorization mode" dialog box. Select "per server ......" In a single region, click "add license" to display the "add customer access license" dialog box. Add an appropriate number in the "quantity" text box. If there are 100 computers in the network, you can add more than 100 computers. Of course, the more users, the more system resources are occupied, and Microsoft's authorization should be confirmed. Click "OK" and "I agree. Construction Cost of rough cable networking Q: When the transmission distance exceeds 185 meters, you can connect to ADSL using a crude cable. How many meters of transmission distance can a rough Cable Support? How much is the price of one meter? Can I use fiber optic cables instead? A: The maximum capacity of a coarse cable is 500 meters. The current crude cable price is about 1 ~ 5 RMB/meter. The cost of the optical fiber is similar to that of the crude cable, but the optical fiber is converted into an RJ45 network cable, and the transfer equipment is relatively expensive. In the case of low network bandwidth usage, the crude cable is preferred (low cost and easy to lay ). No network can configure the Active Directory Q: Can I configure the Active Directory (Active Directory) of Windows 2000 server without network connection? If yes, how can I configure it? A: You can configure the Active Directory if the computer is installed with a NIC but not connected to the network. However, if the NIC is not installed, the Active Directory cannot be configured. However, the following methods can be used: 1. Install the virtual network card provided by Microsoft. On the Control Panel, double-click the "Add/delete Hardware" icon, run the "Add/delete hardware wizard", and select "Add/Remove device fault> Add new device> NO, select hardware> network adapter from the list, select Microsoft from the manufacturer, and select Microsoft loopback adapter from the network adapter to install Microsoft Virtual Network Adapter. Then, set a static IP address for the NIC and set the DNS address as your own IP address. 2. Install the virtual machine. If you want to perform network experiments on a computer, such as active directories, domains, DNS, and DHCP, you only need to install a virtual machine software-vmware workstation, even if no network adapter is installed, you can also set up a network environment to complete various network experiments.

Return

Reply: Always happy (posting: Level 5 member credit: 120 points: 2228) 2005-1-24 8:22:13 ADSL device CRC error The computer in our dormitory is connected to the Internet through ADSL, which is often dropped recently. When you access the ADSL modem management interface, sometimes the data transmission rate is very low, and the number of CRC errors during upload reaches more than 3000 (previously this value was basically 0 ). The line attenuation also reaches around 20, while the computer of the user with the same ISP broadband installed nearby is normal. What is the reason? Virtual dialing protocol error The operating system is Windows 2000 Professional + SP4. It adopts the fttx + LAN method and raspppoe 098c dialing software. After the system is reinstalled, The svhost.exe file is often used incorrectly. In the management tool, the error sources are ipnathlp and Service Control Manager. The event code is 7031, 7002, 7009, 30013, 7000, and 7009, respectively. If an error occurs, you cannot access the Internet again. You only need to restart. What causes these problems? Is there any solution? ASP service frequently stops The servers in our community use Windows2003 + IIS + CGI and provide Web, FTP and other services. asp services are often inaccessible in recent days. The DNS server cannot be pinged. When each machine of the company accesses the internet server, the userenv error is displayed in the log file with the ID 1000. I checked the Microsoft database and said it was a DNS error. Shared Internet access MAC address conflict The operating system of the school server is Windows NT. The assigned IP server sends a dhcpdiscover packet to the DHCP server through the MAC address of the NIC, after receiving the IP address, the server provides a valid IP address to the host. However, some users can trick the DHCP server by modifying the MAC address to obtain the same Internet access permission, but it is unstable. When IP Address resources are insufficient, shared Internet access is unstable. How can this problem be solved? Achieve cross-network access without routing A Windows 2000 Server machine is installed with a dual Nic, which is connected to both A and B. After you configure the route entry of the Windows 2000 server and the "network router" in the remote access, the two network segments can communicate with each other, but there is always a problem that cannot be solved: because both bandwidth a and bandwidth B impose IP restrictions on each other, users of the other side are not allowed to access their own video resources. If you want to watch a broadband video, you must disable the NIC that connects to B's broadband, and vice versa. Modify the MAC address in Win2000/XP In the past, you reported how to modify the MAC address of the NIC by modifying the Registry under Windows 98/me, but the key value cannot be found in Windows 2000/XP. How can I change it?

Return

Reply: Always happy (posting: Level 5 member credit: 120 points: 2229) 2005-1-24 8:22:59 Faults in virtual dialing I am a residential broadband user and use the virtual dialing method (pppoe ). The fault is that, after a few minutes of online connection, sometimes there is no traffic, and the network connection cannot be disconnected at this time, and cancellation is also invalid, Why DHCP address occupation When I set up a wireless network using a D-LINK AP (DWL-900AP), after enabling DHCP occurred strange phenomenon: First open Wireless AP, then open the operating system for Windows 2000 Server server, in this case, all the DHCP addresses of the AP are occupied ,. 255.255.0. Can FTP servers be mounted in residential broadband? My computer is connected to the Internet through a residential server and there is no fixed IP address. Now I want to set up an FTP server to access my computer from the Unit. Is it impossible to implement it without a fixed IP address? How can I use port ing? The client cannot access the Internet normally. Our company uses ADSL Broadband to access the Internet. Although Internet sharing is enabled for the host and the client ie Automatic Detection settings are set, the client cannot access the Internet normally. Why? Increase the remote dialing Rate Remote dialing in my local area network is slow, which affects normal work. There are three modem in the LAN. After a dial-up connection, the network speed is only 9.6 kbps, and the other two are only 33.6 Kbps, and remote search computers are slow.