Strange causes of Web Server faults

With the increasing requirements for informatization, we believe that most organizations will set up their own Web servers to publish information and promote themselves on the Internet. To ensure that any online user can smoothly access the content on the Web server, the network administrator usually needs to set up the IIS server before releasing the Web information, in order to ensure the consistent and stable operation of the website of the organization. However, in many cases, we may encounter Web server access failures. In the face of Web Server failures, we tend to be in disorder and do not know where to start, to solve these Web Server faults. In fact, there are many factors that cause Web Server faults. We need to troubleshoot them one by one to effectively solve the corresponding Web server faults.

Web Server failure

In order to fully display the Organization's image and expand the Organization's visibility, the Organization's leadership asked the network administrator to immediately come up with a solution to build a Web site with personalized characteristics, it not only ensures that employees inside the Organization can access the Web site through the Intranet, but also ensures that Internet users can quickly access the site content of the Organization. In accordance with the spirit of leadership instructions, the network administrator immediately took action and selected a computer with extremely high operating performance as a Server system, and installed and configured Windows Server 2003, at the same time, a Web server is built using the built-in IIS components of the system. To improve the access speed of the Web site, the network administrator specially connects the computer where the Web site is located to the gigabit core switch, at the same time, set the IP address of the target host to the address in the same network segment as the computer used by common employees of the organization. At the beginning, both Intranet users and Internet users can access the website of the organization normally.

However, it does not take long for Intranet users to encounter a Web Server failure when accessing the Web site. The specific manifestation is that no matter which client system is used, when you use an intranet address to access the target site of the Organization, the authentication dialog box is displayed on the System screen, requiring employees of the Organization to enter the access account and password, however, when the network administrator attempts to log on as the system administrator of the Web site, he finds that he cannot log on. what's even more incomprehensible is that the network administrator rushed to the Web server, when I checked its security configuration, I found that the logon verification settings were not enabled for the target Web site. How did the Authentication Dialog Box pop up?

Web Server troubleshooting

As there are many factors that may cause such Web Server faults, We must troubleshoot various possible factors in order to find out the specific causes of Web Server faults, and take targeted measures to quickly solve the fault:

Web Server troubleshooting process 1. Check security Logon Settings

The authentication dialog box is displayed when you access the target Web site. This means that the target Web site may not be correctly configured for secure login, therefore, you must enter an access account when accessing Web content. According to this analysis, the network administrator wants to first check the security login configuration parameters of the Web server to see if the settings are correct. The network administrator wants to immediately come to the target Web host site, log on to the console with a privileged account, and click "start", "set", and "Control Panel". In the displayed system control panel window, find the "Management Tools" icon, double-click this icon to go to the corresponding system management tools List window. Then, double-click the IIS function icon to bring up the corresponding system's IIS Console window, from the list area on the left of the window, find the computer where the target Web site is located, right-click the computer name, and execute the "properties" command from the shortcut menu to bring up the Property setting window for the target Web host; click the "Directory Security" tab in the property settings window to open the directory security option settings page. Next, on the right of the "Identity Authentication and Access Control" setting item on the settings page, click the edit button to go to the authentication and access control Settings dialog box. The Network Administrator finds that "Anonymous Access" and "Integrated Windows Authentication" are all selected. So he tried to unselect these Parameter options and then re-access the Web from a computer on the Intranet, but the same fault still exists, the Network Administrator selects "Anonymous Access" and "Integrated Windows Authentication" again, but he is very disappointed that the above two options are selected or not selected, it seems that all faults exist, which indicates that the security Logon Settings of the target Web host have nothing to do with the fault.

Web Server troubleshooting process 2. Check Directory Access Permissions

Will it be the home directory pointed to by the target Web site, which limits the access permissions of common users? It is suggested that when building an FTP site, if users are not allowed to access the FTP site's main directory, normal users cannot log on to the FTP site through the IE browser. Therefore, the Network Administrator immediately opens the system resource manager window of the target Web site, finds the corresponding home directory, right-click the home directory, and runs the "properties" command from the shortcut menu, open the attribute Setting dialog box for the corresponding home directory. Click the "Security" tab and the network administrator will see that the access permission for the everyone account is not granted, why is access failure on the Web server? To verify that such a guess is correct, the network administrator immediately clicks the "add" button on the Security Options settings page to add the everyone account to the account list, at the same time, an appropriate access permission is set for the account, and then click "OK" to save the settings. The problem was solved as a result, however, when the network administrator tries to access the Web site from a common client system again, it finds that the website still fails. Obviously, the cause of the failure may not be the directory access permission.

Web Server troubleshooting process 3. Check Internet connection settings

Since Logon Settings and permission settings do not affect the failure of access to the Web server, the problem may occur elsewhere. Since the Unit's Web server has been set up successfully, the network administrator rarely changes it, so the possibility of problems on the server itself is relatively small, so the network administrator decided to start from the network connection settings of the common client, check whether it is caused by the client itself.

The Network Administrator is worried that ARP viruses may exist in the LAN, causing the Internet packets to be forcibly forwarded to other hosts when the common client system accesses the target Web site, so he immediately logged on to the core switch background System of the LAN and scanned and diagnosed each port on the intranet using the diagnostic commands provided by the system, the results show that all the Internet ports work normally, and there is no address conflict caused by ARP virus in the Intranet, which indicates that there is no ARP virus in the intranet.

Then, the network administrator tests the network connectivity of several common client systems and finds that their statuses are normal. Then, the Network Administrator executes the ping command from the client system, to test the connectivity of the target Web site IP address, which means that the common client system can normally access the target Web site.

Later, the network administrator worried that the client system would use the proxy LAN to access the Internet, because when accessing the target Web site in this way, you must first enter the Logon account and password of the proxy server, is the authentication dialog box displayed on the System screen for proxy servers when we access a Web site? To eliminate this problem, the network administrator immediately opens the IE browser window of the client system, and then click "Tools"/"Internet Options" to open the Internet option Setting dialog box, click the "connection" tab and on the corresponding tag settings page, the network administrator finds that the local client system does not enable the proxy server settings, this indicates that the failure of access to the Web server does not have any relationship with the online connection settings of the client system.

Web Server troubleshooting process 4. Check authorization mode configuration

After eliminating the factors of the client system, the network administrator again focused on the Web server. After consultation on the Internet, the Network Administrator estimates that the Windows Server 2003 Server System's authorization mode may be accidentally modified, because if the Server authorization mode is not set at the time, it is very likely that the user's Logon account is invalid no matter what he or she enters. To achieve this, the network administrator immediately logs on to the Web server system, click "start", "set", and "Control Panel" commands, and double-click "authorize" in the displayed control panel window, the authorization mode configuration window is displayed. The Network Administrator finds that the target Web site currently uses the "per server" Authorization mode. To determine whether this parameter affects Web access, the Network Administrator changed the authorization mode to the "per device or user" option and restarted the Web server system. However, this adjustment did not achieve any effect, it seems that the authorization mode configuration has no direct impact on Web access operations.

Web Server troubleshooting process 5. Check other Web Services

After the above troubleshooting, the Network Administrator confirmed that the status of the Web server and the client system is normal, and the Intranet line of the unit is normal. Why does the client system access the website of the organization, the authentication dialog box is displayed, and no user account is used? After careful analysis, the network administrator estimated that other Web Services may exist in the LAN at the same time, while other Web Services just grabbed the site address of the Web server, in the end, the company's employees actually access another website that has not been correctly configured during Web access.

Just as the network administrator was preparing to check whether there were other Web Services in the LAN, a faulty phone call suddenly came in, saying that the newly purchased printer could not be printed on the network, will this fault be related to the failure of Web server access? With this in mind, the network administrator immediately rushed to the network printer site, logged on to the background management page of the device, checked its configuration parameters, found that the device's log page prompts that there is an address conflict, after careful consideration, the network administrator finds that the conflicting address is actually the address of the website of the organization. When we access the target site from the Intranet client system, do we access the printer background management system? Since address conflicts exist, the network administrator immediately assigned a new address to the network printer, and then accessed the target Web site again, this time, the corresponding site content was successfully opened, and the Web server fault has been successfully solved.

Web server fault Summary

After more in-depth checks, the network administrator finds that the printer device runs the Web service by default, so that the print user can remotely manage the printing device through the Web; by default, the anonymous access function is not enabled for the network printer. When the network printer uses the IP address of the website, the online user actually accesses the printer background management page, this page requires authentication, which is why the authentication dialog box pops up when a common user accesses the target site. However, the Network Administrator does not enter the user account authorized by the network printer, no matter which user account you enter, the logon fails. This is the cause of the Web Server failure.

Looking back at the Web server troubleshooting process above, we found that the troubleshooting of this Web server is actually very simple. If we can promptly notice the addition of a network printer in the LAN, in troubleshooting, we may be able to notice the impact of this change on Web Server faults. To this end, we should first observe whether there are any changes in the network environment before investigating network faults in the future. If there are any changes, we will start to think about the changes in a targeted way, in this case, the fault will not be resolved.