IIS Log Analysis 2. Error Code Overview

If an IIIs error occurs, first check the error code to find out what the error is and solve the problem accordingly, which will reduce the time.

Http1xx-the status code prompts a temporary response. Before receiving a regular response, the client should be prepared to receive one or more 1xx responses.

* 100-continue.
* 101-switch protocol.

2XX-success

This type of Status Code indicates that the server successfully accepts client requests.

* 200-OK. The client request is successful.
* 201-created.
* 202-accepted.
* 203-non-authoritative information.
* 204-NO content.
* 205-Reset content.
* 206-part of content.

3xx-redirection

The client browser must perform more operations to implement the request. For example, the browser may have to request different pages on the server or repeat the request through the proxy server.

* 302-the object has been moved.
* 304-not modified.
* 307-temporary redirection.

4xx-client Error

The client seems to be faulty when an error occurs. For example, the client does not provide valid authentication information for a page that does not exist in a request.

* 400-Incorrect request.
* 401-Access denied. IIS defines many different 401 errors, which indicate more specific error causes. These specific error codes are displayed in the browser but not in the IIS log:
O 401.1-Logon Failed.
O 401.2-login failed due to server configuration.
O 401.3-the ACL is not authorized due to resource restrictions.
O 401.4-filter authorization failed.
O 401.5-An error occurred while authorizing the ISAPI/cgi application.
O 401.7-the access is rejected by the URL Authorization Policy on the Web server. This error code is dedicated to IIS 6.0.
* 403-Access prohibited: IIS defines many different 403 errors, which indicate more specific error causes:
O 403.1-the execution access is forbidden.
O 403.2-Read access is forbidden.
O 403.3-write access is forbidden.
O 403.4-requires SSL.
O 403.5-requires SSL 128.
O 403.6-the IP address is rejected.
O 403.7-client certificate required.
O 403.8-site access is denied.
O 403.9-too many users.
O 403.10-the configuration is invalid.
O 403.11-password change.
O 403.12-access to the ing table is denied.
O 403.13-client certificate revoked.
O 403.14-reject the directory list.
O 403.15-exceeds the client access permission.
O 403.16-the client certificate is untrusted or invalid.
O 403.17-the client certificate has expired or has not yet taken effect.
O 403.18-the requested URL cannot be executed in the current application pool. This error code is dedicated to IIS 6.0.
O 403.19-CGI cannot be executed for clients in this application pool. This error code is dedicated to IIS 6.0.
O 403.20-Passport Logon Failed. This error code is dedicated to IIS 6.0.
* 404-not found.
O 404.0-(none)-No file or directory found.
O 404.1-unable to access the web site on the requested port.
O 404.2-the Web service extended locking policy blocks this request.
The O 404.3-mime ing policy blocks this request.
* 405-HTTP predicates used to access this page are not allowed (methods are not allowed)
* 406-the client browser does not accept the MIME type of the requested page.
* 407-proxy authentication is required.
* 412-precondition failed.
* 413-The Request Entity is too large.
* 414-the request URI is too long.
* 415-unsupported media type.
* 416-the requested range cannot be met.
* 417-execution failed.
* 423-locking error.

5xx-Server Error

The server cannot complete the request because of an error.

* 500-internal server error.
O 500.12-the application is busy restarting on the Web server.
O 500.13-the Web server is too busy.
O 500.15-Direct Request to global. ASA is not allowed.
O 500.16-unc authorization creden。 are incorrect. This error code is dedicated to IIS 6.0.
O 500.18-the URL authorized storage cannot be opened. This error code is dedicated to IIS 6.0.
O 500.100-Internal ASP error.
* 501-the header value specifies the unimplemented configuration.
* 502-the Web server receives an invalid response when it is used as a gateway or proxy server.
O 502.1-CGI application timeout.
An error occurred in the O 502.2-CGI application. Application.
* 503-the service is unavailable. This error code is dedicated to IIS 6.0.
* 504-gateway timeout.
* 505-the HTTP version is not supported.

Common HTTP status codes and their causes

* 200-success. This status code indicates that IIS has successfully processed the request.
* 304-not modified. The document requested by the client is already in its cache and has not been modified since the cache. The client uses cached copies of documents instead of downloading documents from the server.
* 401.1-Logon Failed. The logon attempt fails, possibly because the user name or password is invalid.
* 401.3-the ACL is not authorized due to resource restrictions. This indicates that NTFS permission issues exist. This error may occur even if you have the relevant permissions on the file you are trying to access. For example, if the IUSR account does not have access to the C: "winnt" System32 "inetsrv directory, you will see this error. For additional information about how to resolve this issue, click the following article number to view the article in the Microsoft Knowledge Base: 187506 (http://support.microsoft.com/kb/187506/) info: Basic NTFS permissions for IIS 4.0

* 403.1-the execution access is forbidden. The following are two common causes of this error:
O you do not have sufficient execution permits. For example, if the directory permission of the ASP page to be accessed is set to "NONE", or the directory permission of the CGI script to be executed is "only allow scripts ", this error message is displayed. To modify the execution permission, right-click the directory in the Microsoft Management Console (MMC), and then click the properties and directory tabs to ensure that the appropriate execution permission is set for the content to be accessed.
O you have not set the script ing of the file type you are trying to execute to identify the predicates used (for example, get or post ). To verify this, right-click the directory in MMC, click Properties, Directory tab, and configuration, and then verify that the script ing of the corresponding file type is set to allow the predicates to be used.
* 403.2-Read access is forbidden. Verify that IIS has been set to allow read access to the directory. In addition, if you are using a default file, verify that the file exists. For additional information about how to resolve this issue, click the following article number to view the article in the Microsoft Knowledge Base: 247677 (http://support.microsoft.com/kb/247677/) error message: 403.2 forbidden: read Access forbidden (403.2 Access prohibited: Read access prohibited)

* 403.3-write access is forbidden. Verify that the IIS and NTFS permissions are set to grant write access to the directory. For additional information about how to resolve this issue, click the following article number to view the article in the Microsoft Knowledge Base: 248072 (http://support.microsoft.com/kb/248072/) error message: 403.3 forbidden: write Access forbidden (403.3 Access prohibited: Write Access prohibited)

* 403.4-require SSL. Disable the require security channel option, or use HTTPS instead of HTTP to access the page. If this error occurs for a web site that does not have a certificate installed, click the following article number to view the article: 224389 (http://support.microsoft.com/kb/224389/) error message in the Microsoft Knowledge Base: HTTP errors 403, 403.4, and 403.5 Prohibit Access: require SSL

* 403.5-SSL 128 is required. Disable the require 128-bit encryption option, or use a browser that supports 128-bit encryption to view the page. If this error occurs for a web site that does not have a certificate installed, click the following article number to view the article: 224389 (http://support.microsoft.com/kb/224389/) error message in the Microsoft Knowledge Base: HTTP errors 403, 403.4, and 403.5 Prohibit Access: require SSL

* 403.6-the IP address is rejected. You have configured your server to deny access to your current IP address. For additional information about how to resolve this issue, click the following article number to view the article in the Microsoft Knowledge Base: 248043 (http://support.microsoft.com/kb/248043/) error message: 403.6-forbidden: IP address rejected (403.6-unavailable: IP address rejected)

* 403.7-client certificate required. You have configured your server as a client authentication certificate, but you have not installed a valid client certificate. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: 190004 (http://support.microsoft.com/kb/190004) error 403.7 or "connection to server cocould not be established" (unable to establish connection with server)
186812 (http://support.microsoft.com/kb/186812/) PRB: error message: 403.7 forbidden: client certificate required (403.7 forbidden access: client certificate required)

* 403.8-site access is denied. You have set domain name restrictions for the domain you use to access the server. For additional information about how to resolve this issue, click the following article number to view the article in the Microsoft Knowledge Base: 248032 (http://support.microsoft.com/kb/248032/) error message: forbidden: site access denied 403.8 (Access prohibited: site access denied 403.8)

* 403.9-too many users. The number of users connected to the server exceeds the connection limit you set. For additional information about how to change this restriction, click the following article number to view the article in the Microsoft Knowledge Base: 248074 (http://support.microsoft.com/kb/248074/) error message: Access forbidden: too connected users are connected 403.9 (Access prohibited: too many connected users 403.9)
Note: Microsoft Windows 2000 Professional and Microsoft Windows XP Professional automatically set a maximum of 10 connections on IIS. You cannot change this restriction.
* 403.12-access to the ing table is denied. The client certificate is required for the page to be accessed, but the user ID mapped to your client certificate has been denied access to the file. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: 248075 (http://support.microsoft.com/kb/248075/) error message: HTTP 403.12-Access forbidden: mapper denied access (HTTP 403.12-Access prohibited: ing Table Access denied)

* 404-not found. This error occurs because the file you are trying to access has been removed or deleted. This error also occurs if you attempt to access a file with a limited extension after installing the URLScan tool. In this case, "rejected by URLScan" appears in the log file of the request.
* 500-internal server error. Many server errors may cause this error message. The Event Viewer log contains more detailed error causes. In addition, you can disable the friendly HTTP Error message to receive detailed error descriptions. For additional information about how to disable friendly HTTP Error messages, click the following article number to view the article in the Microsoft Knowledge Base: 294807 (http://support.microsoft.com/kb/294807) how to disable the "show friendly HTTP Error message" function of Internet Explorer 5 on the server side

* 500.12-the application is restarting. This indicates that you attempt to load ASP pages When IIS restarts the application. After the page is refreshed, this information disappears. If this information appears again after the page is refreshed, it may be that the anti-virus software is scanning the global. Asa file. For additional information, click the following article number to view the article: 248013 (http://support.microsoft.com/kb/248013/) error message in the Microsoft Knowledge Base: HTTP Error 500-12 Application restarting (HTTP Error 500-12 the application is restarting)

* 500-100.asp-Asp error. If the ASP page to be loaded contains the error code, this error message is displayed. To obtain more accurate error information, disable the friendly HTTP error message. By default, this error message is only enabled on the default web site. For additional information about how to see this error message on a non-default web site, click the following article number to view the article in the Microsoft Knowledge Base: 261200 (http://support.microsoft.com/kb/261200) the HTTP 500 error message is displayed, but the ASP error message of 500-100.asp is not displayed.

* 502-Gateway error. If the CGI script to be run does not return a valid HTTP header set, this error message is displayed.

Ftp1xx-Affirmative preliminary reply

These status codes indicate that an operation has started successfully, but the client wants to receive another response before continuing to operate the new command.

* 110 restart and mark the reply.
* 120 the service is ready and starts in NNN minutes.
* 125 the data connection is enabled and transmission is starting.
* 150 the file is in normal state. Prepare to open the data connection.

2XX-a positive response

An operation has been completed successfully. The client can execute new commands.

* 200 command OK.
* 202 if no command is executed, there are too many commands on the site.
* 211 system status or system help reply.
* 212 directory status.
* 213 File status.
* 214 help message.
* 215 name system type, where name is the formal system name listed in the assigned numbers document.
* 220 the service is ready to execute new user requests.
* 221 close the control connection. If appropriate, log out.
* 225 the data connection is opened and is not being transmitted.
* 226 close the data connection. The requested file operation has been successful (for example, transferring a file or dropping a file ).
* 227 enters the passive mode (H1, H2, H3, H4, P1, P2 ).
* 230 The user has logged on and continues.
* The file operation requested by 250 is correct and has been completed.
* 257 "pathname" has been created ".

3xx-Affirmative intermediate reply

The command is successful, but the server needs more information from the client to process the request.

* 331 the user name is correct and the password is required.
* 332 You need to log on to the account.
* 350 the requested file operation is waiting for further information.

4xx-completion of transient Negation

The command fails, but the error is temporary. If the client retries the command, it may be executed successfully.

* 421 the service is unavailable and the control connection is being closed. If the Service determines that it must be disabled, this response will be sent to any command.
* 425 the data connection cannot be enabled.
* 426 Connection closed; Transfer aborted.
* 450 file operations not requested. The file is unavailable (for example, the file is busy ).
* 451 the request is aborted due to an exception: A local error is being processed.
* 452 the requested operation is not performed. Insufficient system storage space.

5xx-permanent completion reply

The command fails. The error is permanent. If the client retries the command, the same error will occur again.

* 500 syntax error. The command cannot be identified. This may include errors such as too long command lines.
* 501 syntax errors are found in parameters.
* 502 the command is not executed.
* 503 error command sequence.
* 504 the command for this parameter is not executed.
* 530 not logged on.
* 532 accounts are required to store files.
* 550 the requested operation is not performed. File is unavailable (for example, the file is not found and no access permission is available ).
* 551 the requested operation is aborted abnormally: Unknown page type.
* 552 the file operation requested is terminated abnormally: exceeds Storage Allocation (for the current directory or dataset ).
* 553 the requested operation is not performed. The file name is not allowed.

Common FTP status code and Its Causes

* 150-FTP uses two ports: 21 for sending commands and 20 for sending data. Status Code 150 indicates that the server is preparing to open a new connection on Port 20 and send some data.
* 226-the command opens a data connection on Port 20 to perform operations, such as file transfer. This operation is successfully completed and the data connection is closed.
* 230-the status code is displayed after the client sends the correct password. It indicates that the user has successfully logged on.
* 331-the status code is displayed after the client sends the user name. This status code is displayed no matter whether the user name is a valid account in the system.
* 426-the command opens the data connection to perform the operation, but the operation has been canceled and the data connection has been closed.
* 530-the status code indicates that the user cannot log on because the combination of the user name and password is invalid. If you log on with a user account, you may enter the wrong user name or password, or you may choose to allow anonymous access only. If you log on with an anonymous account, the IIS configuration may reject anonymous access.
* 550-the command is not executed because the specified file is unavailable. For example, the file to get does not exist, or you try to put the file to a directory without the write permission.