"FFFF.FFFF.FFFF" appear on all switch port and vlan

[ty.chan007]

When i go show mac address table, i got below:

ME01-SCT#sh mac address-table multicast 

Multicast Entries

 vlan    mac address     type    ports

-------+---------------+-------+--------------------------------------------

   1    0100.0ccc.ccce   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   1    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   2    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   3    ffff.ffff.ffff   system Gi1/3,Gi1/6,Gi1/8,Gi1/10,Gi1/11,Gi1/12,Gi1/15

                                Gi1/20,Gi1/21,Te1/29,Po3

   4    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   5    ffff.ffff.ffff   system Gi1/3,Gi1/8,Gi1/10,Gi1/15,Gi1/20,Gi1/21,Te1/29

                                Po3

   6    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   7    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   8    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

   9    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  10    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  11    ffff.ffff.ffff   system Gi1/3,Gi1/6,Gi1/8,Gi1/11,Gi1/12,Gi1/15,Gi1/20

                                Gi1/21,Te1/29,Po3

  12    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  13    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  14    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  15    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  16    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  17    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  18    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  19    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  20    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

  21    ffff.ffff.ffff   system Gi1/3,Gi1/15,Gi1/20,Gi1/21,Te1/29,Po3

I see ffff.ffff.ffff  in all vlans and connected trunk ports. is it normal or some kind of loop or attack ?

Regards,

chanty

[ty.chan007]

any comment?

[Mark Malone]

Take a look at this

https://supportforums.cisco.com/discussion/11507571/why-some-switch-ports-does-not-show-mac-address

try clear the mac address, bounce the port check the arp table etc and make sure the end devices are up and powered on fully

[ty.chan007]

Hi, thanks for response.

All those ports are trunks and  connected to Trunk port of other switches like Catalyst switch and Bridge-domain in ASR 9K. The port that connected to Catalyst switch also appear FFFF... learned but i don't see FFFF... in the Catalyst switch itself.

BTW, there is no command to clear MAC address multicast table.