Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

Daniel_55334's avatar
Daniel_55334
Icon for Altostratus rankAltostratus
May 26, 2008

What exactly does FastL4 profile do?

Customer have to load balance a webserver. Using default settings it takes more than 10 seconds to completely load the webpage. After using the FastL4 profile it takes only 3 seconds. So what does it ...
config
design
dennypayne's avatar
dennypayne
Icon for Employee rankEmployee
May 27, 2008
It means that you can't be trying to process anything above Layer 4. So no iRules, no header insertions, no cookie persistence, etc.

 

 

But, on a virtual server that does not require any Layer 7 decision-making, using the FastL4 profile will cause the connection to be processed in the PVA (the Packet Velocity Accelerator ASIC on LTM) and can give you greater performance.

 

 

See SOL 4832 (Click here) for an explanation of the various configuration options that will cause the PVA to be in either Full or Assisted mode.

 

 

Hope that helps,

 

Denny