Always Geeky

By default, a HTTP or HTTPS monitor will not fail a member if the LTM receives something other than a 200 OK response. This can be confusing, as you would expect a 404, 500, 501, 302 or similar response to cause a failure.

This is expected behaviour, due to the receive string being blank. When this field is blank, ANY response from a web server is considered a pass, including a non 200 response. This allows the monitor to check that the web server is actively responding to HTTP requests, regardless of how it is responding.

To mark the member up only when a 200 response is received, you must set the receive string. A typical example would be to set the string to “200 OK”, as this will mark the member up for a normal response, but mark it down for any other response such as a 404 or 500.