GTM irule to return differnt pool

Im trying to trace out what is happening on the gtm atm, as Im trying to write an irule for the above mentioned issue, is there a way to catch in general any request in an irule ?

 

 

I have tried "when DNS_REQUEST" which should catch what I what however log local0 does not appear to catching the dns request i.e.

 

 

log local0. "Connection from: [IP::remote_addr] ..."

 

 

I've tried client_addr as well and nothing