IRules & CPU

SSHSSH, the simple fact you are using iRules most likely means that the data in each packet/connection/request needs to be inspected, hence the CPU overhead. If you use a Performance (Layer 4) or Forwarding VS and iRules that don't operate above layer 4 then these are mostly handled in hardware/on the forwarding plane.

 

 

There isn't an easy separation between the two planes I'm afraid, certainly not in the SDN sense. Although TMM (and thus LTM) and the HMS run different operating systems they 'share' RAM and (a single) CPU and one is dependent on the other. However, as I said use the right type of VSs and things get handled directly in hardware. If you can't then expect the traffic load to have an affect on CPU.