Troubleshooting a Web server

Access to the Web server is a lot of LAN users often have to do a "homework", in the frequent access process, many friends have accumulated some Web server access experience, these experiences will often help them to quickly solve some of the small inaccessible problems. However, this article contributed to the Web server can not access the failure of the phenomenon is more special, if not carefully analyzed, simple experience to solve the problem, mostly easy detours; In order to help your friends to access the Web server efficiently, I now restore this special network access troubleshooting process, I hope you can get inspiration from it! Can ping but can't access a unit LAN is not large, a total of 18 ordinary computers, plus a Web server with Windows Server 2003 system installed, all normal computers and Web servers are all connected to a manageable core switch, And through the broadband router to achieve local area network sharing Internet. At ordinary times, 18 ordinary computers installed on the operating system is not the same, there are Windows XP system, Windows Vista system installed, and two computers are still in use Windows 98 system, However, these computers can normally access the Web server on the local area network. However, in recent time, the LAN user through IE browser access to Web server site content, the system screen unexpectedly appears the authentication dialog box, asking the user to enter the appropriate user name and password information; in fact, the Web server does not have authentication enabled at all, It can normally allow any user on the LAN to log in anonymously, access the content of the site, then why is this happening now? What's even more surprising is that network administrators cannot successfully authenticate to the Web server, regardless of whether they enter a legitimate user account for a Web server or enter a Super Administrator account. When the network administrator tries to test the connectivity of the LAN target Web server by using the ping command, it is found that the Web server can be properly ping, which also proves that the physical connection between the normal computer on the LAN and the Web server is normal; A failure to access the Web server is likely to occur, which is probably the problem with the Web server itself. Check Web site access permissions at first, the network administrator thought that the Web server itself was improperly set up, which caused the LAN user not to visit normally. Considering that the Web server suddenly requires authentication, the network administrator determines that the Web server's access rights are accidentally modified, and immediately enters the Windows Server 2003 Server system, clicking Start/Settings/Control Panel, and then double-clicking Administrative Tools icon, and then double-click the IIS control icon in it to open the IIS console window for the corresponding system from which to findThe site name of the target Web server, and then right-click the target site name. To perform the Properties command in the right-click menu, open the Properties Settings window for the target site, click the Directory Security tab in the Settings window, and click the Edit button in the authentication and access control section of the corresponding Option settings page , open the Settings dialog shown in Figure 1, where the Web server still authenticates, regardless of the option to select or uncheck Anonymous access, Integrated Windows authentication, which indicates that this symptom is not related to the access permission settings of the target Web server. Check server connection restrictions since the entry of a legitimate user account, or even a Super Administrator account, does not correctly log in to the Web server, the network administrator is beginning to suspect that the Windows Server 2003 Server system may limit the number of concurrent connections to users. Because once you limit the number of user connections to the Web server's site home directory, users who have deferred logins will not be able to access site content on the Web server anyway. With this in mind, the network administrator first opens the Resource Manager window for the server system. Locate the site home directory for the Web server, right-click the directory icon, execute the Properties command on the shortcut menu, open the Properties Settings window for the target site's home directory, and click the Sharing tab in the Settings window. In the corresponding Option settings page, the network administrator found that the Windows Server 2003 Server System limited the number of user accesses to the directory to 5, and then tried to modify the parameter to 20 while saving the set operation and then accessing the Web server again. The same symptom continues to occur. Later, when the network administrator queried the user connection limit information, found that the Windows Server 2003 Server system if the licensing mode is not set at that time, the number of users connected to the phenomenon of limited. Search for such a result, the network administrator secretly excited, it seems that the Web server can not access the phenomenon of failure will soon be resolved; He immediately opens the Start menu of the Windows Server 2003 Server system, clicking the Settings/Control Panel command, and then double-clicking the The "Licensing" option, in which the network administrator discovers that the server system chooses the "Per Server" option by default, and that the number of user connections is displayed as "5", it is clear that the parameters are not set correctly. The network administrator immediately selects the "Per Device or user" option here (as shown in Figure 2), then selects the "I agree" option in each device or per-client Licensing dialog box, and then restarts the server system; I thought such an effort would surely reap, However, when you re accessing the LAN Web server from a normal computer, there is an annoying authentication dialog on the system screenBox。 The reason for the unexpected failure is that the network administrator has no clue a local area network user suddenly ran to the network administrator for help, said their department in order to work needs, recently bought a network printer, the network printer connected to the unit's core switch, and set up the relevant network printing parameters, All the users in their department are able to use the network printer to print the material normally, but today, his computer cannot use the network printer, while others can print the network normally. Hearing the user's help, network administrator immediately came to the scene of the network printer, login to the printer background management interface, accidentally opened the network printer log page, found that the IP address of the network printer and the local network of a computer IP address conflict, and then carefully check the conflicting IP address, Unexpectedly is the Web server uses the IP address, no wonder the Web server is not normal access, the original network printer's IP address and its use of the IP address of an accidental conflict. Originally, in order to manage and maintain conveniently, the network printer also runs a Web service, the user through the Web form of the background management interface, can be very easy to set the network printer's various internet parameters, but the network printer with the Weh server in the default state does not support anonymous access. When the user sets the IP address of the network printer and the Web server address conflict, the LAN user again enters the Web server's IP address in the address bar of IE browser window, actually accesses the network printer's backstage login interface, This is why the authentication dialog box appears on the system screen when accessing the Web server. When you use ping to test the connectivity of your Web server, you test the network printer so that a network printer can be ping, but you need to enter a legitimate user account to access it. After figuring out the cause of the failure, the network administrator immediately modified the IP address of the network printer to ensure that the IP address of the Web server did not conflict with the IP address of other computers, and the result was that when the Web server was accessed again, it was able to open the page content quickly. The symptom that the Web server can ping but cannot access is successfully resolved. Finally, the conclusion of this network failure to solve the problem is not very complex, the root of the problem can find the ultimate reason. However, this failure reminds us of each of our network administrators from another angle, solve network failure can not blindly apply experience, but should first be familiar with the latest changes in the network environment before the fault, familiar with the work environment of various network equipment features, only know the latest changes in the network and network equipment of various characteristics, We will be in the face of network failure, subconsciously thinking and Lenovo, only in this way can quickly find specific fault reasons, and can take timely measures to quickly resolve network failures.