how do I determine mac address for this interface fa2/27.It says all ffff.ffff.ffff

SWitch #sh mac-address-table int fa2/27
Multicast Entries
 vlan    mac address     type    ports
-------+---------------+-------+-------------------------------------------
   9    ffff.ffff.ffff   system Switch,Fa2/6,Fa2/7,Fa2/8,Fa2/9,Fa2/17,Fa2/20
                                Fa2/21,Fa2/26,Fa2/27,Fa2/29,Fa2/30,Fa2/34
                                Fa2/42,Fa2/45,Fa2/46,Fa3/1,Fa3/5,Fa3/18,Fa3/31
                                Fa3/37,Fa3/40,Fa3/41,Fa3/43,Fa3/46,Fa3/47
                                Fa3/48,Gi4/3,Gi4/4,Gi4/20,Gi4/22,Gi4/24,Gi4/26
                                Gi4/35,Gi4/36,Gi4/37,Gi4/38,Gi4/39,Gi4/41
                                Gi4/42,Gi4/43,Gi4/47,Gi4/48,Gi5/1,Gi5/2,Gi5/4
                                Gi5/5,Gi5/6,Gi5/7,Gi5/8,Gi5/9,Gi5/11,Gi5/12
                                Gi5/13,Gi5/16,Gi5/18,Gi5/21,Gi5/22,Gi5/30
                                Gi5/33,Gi5/36,Gi5/37,Gi5/41,Gi5/42,Gi5/43
                                Gi5/45,Gi5/46,Gi6/9,Gi6/10,Gi6/11,Gi6/12
                                Gi6/13,Gi6/14,Gi6/22,Gi6/27,Gi6/34,Gi6/41
                                Gi6/44