APM - SSL VPN Client Side check based on pre-defined list of MAC ADDRESSES

You can add (4) after the chkmac_iRule_Event

Try this, there was typo earlier

when ACCESS_POLICY_AGENT_EVENT {
   if { [ACCESS::policy agent_id] eq "chkmac" } {
      set mac [ACCESS::session data get "session.machine_info.last.net_adapter.list.\[0\].mac_address" ]
      if { [class match $mac equals macDG] } {
         ACCESS::session data set "session.logon.custom.chkmac" 1
      } else {
         ACCESS::session data set "session.logon.custom.chkmac" 0
      }
   }
}