Bug ID 991501: Pool members with HTTPS monitor may be incorrectly marked down.

Last Modified: Jun 15, 2024

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
16.0.1, 16.0.0, 15.1.0, 14.1.4, 14.1.3.1, 13.1.3.5

Opened: Feb 09, 2021

Severity: 2-Critical

Symptoms

A pool with an HTTPS monitor may have its members marked down due to the monitor not being able to find a matching cipher for the SSL connection. This occurs when the @STRENGTH keyword is provided in the cipher suites list in the server SSL profile used by the HTTPS monitor, because bigd does not handle this keyword correctly.

Impact

Pool members are wrongly marked down, preventing them from handling incoming traffic.

Conditions

Problem is observed when all conditions listed below are met: - The db variable bigd.tmm set to disable (default setting). - Pool is using an HTTPS monitor. - The HTTPS monitor uses a custom server SSL profile. - The server SSL profile uses a cipher string with @STRENGTH keyword.

Workaround

1. Select the cipher group instead of cipher suites in the server SSL profile. 2. Manually enter the ciphers in the desired order.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips