Bug ID 937649: Flow fwd broken with statemirror.verify enabled and source-port preserve strict

Last Modified: Feb 07, 2024

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

Known Affected Versions:,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,

Fixed In:
17.1.0, 16.1.4, 15.1.9

Opened: Aug 18, 2020

Severity: 2-Critical


Flow forwarding does not work with statemirror.verify enabled and source-port is preserve strict. Depending on the number of tmms and the IP addresses/ports on the network, this causes return traffic to get dropped. Traffic captures show packets leaving the BIG-IP system on one tmm and being returned on another. The return traffic that encounters the second tmm is dropped.


Server-side return traffic to the BIG-IP is dropped. This causes connection timeouts and resets.


-- Mirroring is enabled. -- High availability (HA) peer is connected. -- The source-port setting is preserve-strict. -- The statemirror.verify option is enabled. -- There is more than one tmm.


-- Disable statemirror.verify, disable source-port preserve-strict, disable mirroring. -- On BIG-IP Virtual Edition (VE), add the following to tmm_init.tcl on both units and restart tmm: ndal ignore_hw_dag yes

Fix Information


Behavior Change

Guides & references

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