LTM stream profile: Multiple replacements & regular expressions

Starting in BIG-IP LTM versions 9.3.1 and 9.4.2, the Stream profile must be enabled after the stream expression is first evaluated. This step allows the BIG-IP iRule system to evaluate the expression first before allowing the Stream profile to be enabled. This behavior protects from misconfiguration, which could result in a crash.

 

 

For example:

 

 

when HTTP_RESPONSE {

 

STREAM::expression "@abc@123@"

 

STREAM::enable

 

}

 

 

If the Stream profile is enabled before the expression is evaluated, an error message will be reported to the /var/log/ltm file that appears similar to the following example:

 

 

tmm tmm[1882]: 01220001:3: TCL error: Rule stream_irule - Operation

 

not supported (line 1) invoked from within "STREAM::enable"

 

 

This error message is reported in BIG-IP LTM versions 9.3.1, 9.4.2, and later when the following iRule is used:

 

 

when HTTP_RESPONSE {

 

STREAM::enable

 

STREAM::expression "@abc@123@"

 

}

 

 

http://support.f5.com/kb/en-us/solutions/public/8000/200/sol8207.html