Bug ID 1019429: CMP Forwarded flows do not get syncache counter decremented when only server-side is PVA accelerated

Last Modified: May 29, 2024

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

Known Affected Versions:
15.1.2,, 15.1.3,, 15.1.4, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,,

Fixed In:

Opened: May 18, 2021

Severity: 3-Major


Virtuals with CMP forwarded flows and PVA acceleration may see a higher than expected syncache counter which can lead to permanent syncookie activation. Also, under certain conditions the internal listeners used for config-sync may have syncookies activated. Logs will show the syncookie counter increasing after every activation. bigip1 warning tmm1[18356]: 01010038:4: Syncookie counter 9830 exceeded vip threshold 2496 for virtual = bigip1 warning tmm1[18356]: 01010038:4: Syncookie counter 9834 exceeded vip threshold 2497 for virtual =


Elevated syncache_curr, epva_connstat.embryonic_hw_conns, epva_connstat, embryonic_hw_tcp_conns stas. Improper syncooke activation. Syncookie activation on the config-sync listener may cause config-sync to fail.


-- Virtual servers with CMP forwarded flows - commonly occurring when the FTP profile is in use. -- A platform with PVA acceleration enabled. -- Only the server-side flow of a connection is offloaded to hardware.


Remove the ftp profile or disable PVA acceleration: modify sys db pva.acceleration value none

Fix Information

Counters are now correctly decremented.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips