Update monitor-application-gateway-reference.md

updating error codes

Signed-off-by: MJyot <[email protected]>

Author: MJyot

articles/application-gateway/monitor-application-gateway-reference.md

@@ -335,8 +335,8 @@ If the application gateway can't complete the request, it stores one of the foll
 | ERRORINFO_HTTP_NO_HOST_HEADER | Client sent a request without Host header. |
 | ERRORINFO_HTTP_TO_HTTPS_PORT | The client sent a plain HTTP request to an HTTPS port. |
 | ERRORINFO_HTTPS_NO_CERT | Indicates client isn't sending a valid and properly configured TLS certificate during Mutual TLS authentication. |
-| ERRORINFO_INVALID_HEADER (5xx) | Indicates that the Host header in the HTTP request sent by the client has issue with the structure, syntax, or content, preventing it from correctly processing and forwarding the request to the backend. |
-| ERRORINFO_CLIENT_TIMED_OUT | The Application Gateway timed out because the client's HTTP request has taken too long to send the entire request to the Application Gateway due to client-side issues, a large payload, or a slow network connection. The default timeout is 60 seconds. |
+| ERRORINFO_INVALID_HEADER (4xx) | Indicates that the HTTP request from the client contains a malformed or improperly structured Host header, which prevents the Application Gateway from correctly processing and routing the request to the backend server |
+| ERRORINFO_CLIENT_TIMED_OUT | This error indicates that the client terminated the connection because it did not receive a response from the backend server within its configured timeout period. This is typically caused by a backend server that is slow, overloaded, or experiencing operational issues. |
 | ERRORINFO_REQUEST_URI_TOO_LARGE | This error indicates URL in an HTTP request exceeds the maximum length that the server is configured to accept. The default limit on URL length (including query parameters), is 8kb |
 | ERRORINFO_REQUEST_HEADER_TOO_LARGE | This error indicates that the total size of the HTTP request headers sent by the client exceeds the 32KB limit enforced by Application Gateway. Please note that this limit is fixed and cannot be customized. |
 | ERRORINFO_REQUEST_URI_UNSAFE | This error shows that the WAF found unsafe or malformed content in the request URI. Check the WAF logs to see which rule was triggered and decide if the request was malicious or mistakenly flagged, possibly needing WAF rule adjustments. |