Canopy MIBs and private host mac address

Hi to all!

I’m having a little problem with the SNMP MIBs of motorola.
In the web page has a OID for the SM, that returns the private host mac address but when I’m trying an snmpget with this OID nothing comes as an output!!!

Can anyone help me with this one???

I have canopy r. 7.3.6 or tell me how can i have the host mac addresses of those behind the SMs with an snmp request???

Thanks for your time!