Bug ID 935801: HSB diagnostics are not provided under certain types of failures

Last Modified: Oct 16, 2023

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

Known Affected Versions:
13.1.4,, 13.1.5,

Fixed In:
16.1.0, 15.1.2,

Opened: Aug 12, 2020

Severity: 3-Major


In rare cases where the HSB detects an error and triggers a high-availability (HA) failover, HSB-specific diagnostic data is not provided. An example are XLMAC errors, which can be seen in the TMM logs: <13> Jul 25 18:49:41 notice The number of the HSB XLMAC recovery operation 11 or fcs failover count 0 reached threshold 11 on bus: 3. <13> Jul 25 18:49:41 notice high availability (HA) failover action is triggered due to XLMAC/FCS erros on HSB1 on bus 3.


There is less HSB data for analysis when an internal HSB occurs.


The HSB detects an internal error.



Fix Information

Dump HSB registers on all HSB-initiated high-availability (HA) failovers.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips