Bug ID 524107: When editing an iRule with regular expressions (regex), an incorrect warning is thrown out to LTM log.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:

Opened: May 19, 2015

Severity: 4-Minor

Related Article: K59415918


When trying to use special regex metacharacters (for example, \s for whitespaces, \d for digits, and so on), the system posts a warning to the LTM logs, suggesting a change to the syntax, however, making the change as suggested prevents the correct iRule behavior.


System logs a warning that recommends an incorrect resolution. If you make the change as recommended, the iRule behavior does not work correctly. The error messages appears similar to the following: warning mcpd[8501]: 01071859:4: Warning generated : /Common/test_regex:4: warning: ["\d" has no meaning. Did you mean "\\d" or "d"?][{number=(\d+)}].


Writing an iRule that uses metacharacters in a regular expression.


Ignore the LTM log warning. Use the regex metacharacters without modification.

Fix Information

When editing an iRule with regular expressions (regex), you can use the regex metacharacters without modification, and the system does not recommend an incorrect resolution.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips