HTTP Errors <httpErrors>

errorMode

Optional enum attribute.

Specifies whether HTTP errors are enabled.

The errorMode attribute can be one of the following values; the default is DetailedLocalOnly.

Table 4
Value	Description
`DetailedLocalOnly`	Returns detailed error information if the request is from the local computer, and returns a custom error message if the request is from an external computer. The numeric value is `0`.
`Custom`	Replaces the error that the module or server generates with a custom page that you specify. This mode is useful in providing friendlier error messages to end users. Note: This setting turns off detailed errors, even for local requests. The numeric value is `1`.
`Detailed`	Sends detailed error information back to the client. This mode is useful for testing and debugging Web sites and applications. The numeric value is `2`.

existingResponse

Optional enum attribute.

Specifies what happens to an existing response when the HTTP status code is an error, i.e. response codes >= 400.

The existingResponse attribute can be one of the following values; the default is Auto.

Table 5
Value	Description
`Auto`	Leaves the response untouched only if the SetStatus flag is set. The numeric value is `0`.
`Replace`	Replaces the existing response even if the SetStatus flag is set. The numeric value is `1`.
`PassThrough`	Leaves the response untouched if an existing response exists. The numeric value is `2`.

HttpErrorsSection Class

The following table lists the possible values for the ErrorMode property. The default is 0 (DetailedLocalOnly).

Table 4
Value	Keyword	Description
0	`DetailedLocalOnly`	A detailed error response is generated only if the request comes from the local computer. If the request comes from an external address, the server generates a custom error response. Note: The value of the `ExistingResponse` property determines whether a detailed or custom error is generated.
1	`Custom`	The error that the module or server generates is replaced by a custom page that you specify. This mode is useful in providing friendlier error messages to end users. Note: This setting turns off detailed errors, even for local requests.
2	`Detailed`	A page with detailed information about the application error is displayed, and custom errors are not shown. This mode is useful for testing and debugging Web sites and applications. Note: It is a security risk to set `ErrorMode` to `Detailed`, because even remote clients will receive detailed error information that could lead to unwanted information disclosure.

The following table lists the possible values for the ExistingResponse property. The default is 0 (Auto).

Table 5
Value	Keyword	Description
0	`Auto`	The response depends on the first successful match of the following set of ordered conditions: 1. If the IHttpResponse::SetStatus method was called by using the `fTrySkipCustomErrors` flag, the existing response is passed through, and no detailed or custom error is shown. 2. If the `ErrorMode` property is set to `Custom`, the response is replaced. 3. If `ErrorMode` is set to `Detailed` and there is an existing response, the response is passed through. 4. If `ErrorMode` is set to `Detailed` and there is no existing response, the response is replaced with a detailed error.
1	`Replace`	The existing response is always replaced, regardless of how `SetStatus` was called.
2	`PassThrough`	The existing response is always used.