Multicast address

[ney25]

Hi NetPro,

does anyone knows what does it mean as the multicast address and type as below :

Multicast Entries

vlan mac address type ports

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

10 ffff.ffff.ffff system Fa2/1,Fa2/3,Fa2/4,Fa2/5,Fa2/12,Fa2/17,Fa2/18

Fa2/26,Fa2/27,Fa2/30,Fa2/31,Fa2/32,Fa2/36

Fa2/37,Fa2/39,Fa2/40,Fa2/42,Fa2/43,Fa2/47

Gi1/1

regards,

Jack

[Bobby Thekkekandam]

This is specific to the Cat4000 platform. This is an implementation detail to maintain the broadcast domain for a vlan. As you can see it is a system programmed entry and it is programmed in hardware when a vlan gets created. As the ports in that vlan becomes active, they will be added to this multicast entry. You may see a "Switch" under the ports column, which indicates that the broadcast will be sent to the CPU also. This is usually the case when you configure an IP address for that vlan and you want the ARP broadcast pkts to be sent to the CPU.

Hope that helps,

Bobby