Last Modified: Apr 28, 2025
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1
Fixed In:
13.1.0, 12.1.3
Opened: Jan 11, 2017 Severity: 3-Major Related Article:
K77010072
Two 'Diameter_monitor' instances probing the same server (IP/port) from different pools may interfere with each other, causing one of the monitor instances to fail. This is caused by a possible race in creating a PID file for this 'Diameter_monitor' configuration.
One Diameter monitor may fail, while the other Diameter monitor to the same server IP/port succeeds. On subsequent probe-retry, the failed monitor may now succeed.
Configuration with multiple Diameter monitors probing the same server IP/port.
A possible work-around is to establish different monitor periods for the two pools (such as 28 seconds and 31 seconds), so a simultaneous probe-collision will fail one monitor once, which upon retry will succeed (as three monitor failures are required for a virtual server to be marked down).
The fix includes the monitor-template name in the generation of the PID file, which ensures multiple Diameter monitor instances probing the same server (IP/port) do not interfere with each other.