Bug ID 1039553: Non-200 HTTP status codes fail to be matched by GTM HTTP(S) monitors

Last Modified: Nov 07, 2022

Bug Tracker

Affected Product:  See more info
BIG-IP DNS, GTM(all modules)

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2, 16.1.0, 16.1.1, 16.1.2

Fixed In:
17.0.0, 16.1.2.1, 15.1.5

Opened: Aug 10, 2021
Severity: 3-Major

Symptoms

GTM virtual servers have the wrong status (up when they should be down, or down when they should be up, depending on the monitor's configuration).

Impact

The system incorrectly considers all non-200 responses a failed monitor attempt, despite what the user specified as acceptable status codes in the monitor's configuration. As a result, the availability status reported for a virtual server may be incorrect. This may cause the GTM system to send traffic to unsuitable resources causing application disruptions.

Conditions

-- The GTM virtual servers are monitored with an HTTP or HTTPS monitor that performs HTTP status matching. -- The monitor tries to match an HTTP status code other than 200 (for example, 301). -- The monitor uses HTTP version 1.0 or 1.1 for the request (the default is 0.9).

Workaround

You can work around this issue in any of the following ways: -- Use HTTP version 0.9 for the monitor requests. -- Match on the 200 HTTP status code. -- Do not use HTTP status matching altogether.

Fix Information

GTM HTTP(S) monitors using HTTP version 1.0 or 1.1 can now successfully match status codes other than 200 in the response.

Behavior Change