iRule optimization

It seems this rule will accomplish your goal by filtering off 3 suspicious groups of traffic while allowing other traffic through to the main pool.

Each request coming to the virtual server where the iRule is applied will be evaluated within the HTTP_REQUEST event before the iRule can determine where to send the request.

You could optimize slightly by catching the IP address match when the client first connects:

 when CLIENT_ACCEPTED {
  if { [matchclass [IP::remote_addr] equals $::blacklisted_clients] } { 
    pool Bots
    event disable all
  }
 }
 when HTTP_REQUEST {
  if { [matchclass [HTTP::header User-Agent] contains $::blacklisted_useragents] } { 
    pool Bots
  } elseif { [string first -nocase "bot" [HTTP::header User-Agent]] >= 0 } { 
    pool Bots
  } else { 
    pool MainPool
  }
 }

HTH

/deb