Bug ID 846977: TCP:collect validation changed in 12.0.0: the first argument can no longer be zero

Last Modified: Jul 02, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP Install/Upgrade, LTM(all modules)

Known Affected Versions:
12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 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, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,,, 13.1.3,,,,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,,, 14.1.2,,,,,,, 15.0.0, 15.0.1,,,, 15.1.0,,,

Opened: Nov 07, 2019
Severity: 3-Major


Validation for TCP::collect was changed in BIG-IP software v12.0.0 (with the introduction of JET specifications). Prior to 12.0.0, there were no restrictions on the values of the two arguments. As of 12.0.0, the first argument ('collect_bytes') must be a positive integer, and the second argument ('skip_bytes) must be a non-negative integer. Occurrences of 'TCP::collect 0 0' in iRules experience issues when upgrading to a newer version, producing warnings in LTM log: /Common/T_collect:9: warning: [The following errors were not caught before. Please correct the script in order to avoid future disruption. "invalid argument 0; expected syntax spec:"136 17][TCP::collect 0 0].


Warning in the LTM log file. The iRules containing 0 values do not function as expected. There is no other impact.


-- Using a version of BIG-IP software earlier than 12.0.0, configure an iRule with a 'TCP::collect 0 0' command. -- Upgrade to 12.0.0 or later.


Change 'TCP::collect 0 0' to a value other than 0 (zero) in any iRules before or after upgrade.

Fix Information


Behavior Change

TCP::collect now restricts its first parameter ('collect_bytes') to a positive integer, and its second parameter ('skip_bytes') to a non-negative integer.