Alert if MAC address is changed ?

Hello All,

Is it possible to alert from NPM if MAC address is changed ?

Eg: If ADSL device 'A' with ip address 10.1.1.2 is being polled by NPM and another ADSL device 'B'  has been replaced device 'A' .Device B will have same config(IP address,etc) as device A. In this case,is it possible to get an alert from NPM stating that MAC has been changed for device A???????????????